Why didpeople ferment Macrozamia sarcotesta? Was it to detoxify it?
It is our contention that over many thousands of years of trial-and-error and empirical scientific observations, the Noongar developed their own unique and sustainable food processing techniques, in particular the controlled anaerobic fermentation of the fruit (seed covering, outer rind) of Macrozamia to enhance its taste and nutritive value and to make it easier to remove from the seed which was not eaten. We question the belief that has been perpetuated since colonial times that indigenous processing of this fruit was primarily for the purpose of detoxification.
The Noongar of southwestern Australia are unique in that they were the only Aboriginal group in Australia that consumed the processed red fruit sarcotesta of Macrozamia. Their methods of soaking and/or burying the fruit can best be described as a process of “fermentation.” By contrast Aboriginal groups living in Eastern Australia consumed only the processed seed (starchy endosperm) and discarded the oil-rich sarcotesta. Their processing methods relied heavily on water-leaching and cooking to detoxify the seed prior to consumption for it is scientifically well established that the seed kernel of Macrozamia is highly toxic
We have always been curious as to why Noongar people traditionally fermented and consumed only the sarcotesta. Was their unique method of anaerobic fermentation an adaptation to the water-scarce environment of southwestern Australia at the time (late summer/ autumn) or was it their ancient knowledge that fruit fermentation improved the taste and provided a valuable source of high energy fat and nutrition (e.g. vitamin A)?
Certain early African populations of hunter gatherers (such as the San and the Hadza) are starting to be recognised for their unique and highly diverse gut microbiome which has enabled them to consume a wide range of bush foods found only in their localised environments. Similarly, we maintain that Noongar people must have evolved these specialised adaptations in their gut biome that enabled them to digest and store quantities of fats and fat-soluble vitamins (such as Vitamin A and D) which derived from foods rich in beta-carotenes such as the Macrozamia sarcotesta. Their gut microbiome would also have adapted over time to tolerate any bitter-tasting or toxic residues that may have been present in their plant food sources. We do not discount the possibility that if there were any residual traces of glycosoides (such as cycasin or macrozamin) remnant in the sarcotesta after processing (either from residual toxin or oil rancidity) that these would have been tolerated without inducing ill-effects.1
Traditionally bayoo was processed prior to consumption
This highly prized seasonal food source was traditionally known by different names one of which is bayoo (or its variant renditions baayoo, baio, by-yu, boya, boyah, boy-oo, poio or boy, depending on recorder or geographic region). Ngilgee, one of Daisy Bates’ informants (cited in Abbott 1983: 6), records the name as baian in the Vasse area and the linguist Von Brandenstein (1988: 51) similarly records it as pauyin –‘Zamia palm nuts or seeds.’ These are possibly variants of baio, the term first recorded by Moore in 1835. We would suggest that bayoo (baio) may allude to an egg, stone or oil (fat), depending on the context of reference.
Were the indigenous informants possibly using a descriptor name to refer to the ovoid shaped egg-like fruit (pooyiore, bwye “egg”) or seed?
Drummond (1842) records boya as the nut of the zamia. The terms boya, baio, by-yu, boyoo, pauyain as already noted may be interpreted in a number of ways. The meaning may have derived from boyan (or boin) which translates as oil or fat; boen, flesh (Lyon 1833); boye, boyee or boya denoting stones or boyer “little stones” (Bussell n.d.) or possibly “egg” (see Bindon and Chadwick 1992: 16, 21). We think the egg metaphor may be a reference to the ovoid shape of the seed or alternatively, a biological referent to the propagative part of the plant derived from the female cone.
Bussell (n.d.) records the Noongar name for the ‘native palm’ (Macrozamia reidlii) as “biana.” This may be a descriptor explaining how the fruit was buried. Moore (1842:10) translates bian as meaning ‘to dig’ or ‘to bury’ (past tense, biana). We think Bussell’s informant was probably explaining how the food was prepared. “Descriptors” were commonly used to describe how plants were identified, prepared, consumed or otherwise used.
Djirij – a totemic name for the Macrozamia?
A common name for the Macrozamia plant in the Perth and surrounding area is djiriji (Moore 1842: 30), dyergee (Lyon 1833), girijee “(“the Zamia tree,” Grey 1840: 42), dji-ri-ji (Symmons 1841), djir-jy (Stokes 1846) or jeerja (Joobaitch, Daisy Bates’ informant). Possibly this name has mythological significance. It may even be a totemic referent deriving from the association of Macrozamia with a version of the fire-recapture mythological narrative. In one version of this myth, the hawk, after retrieving the nut containing the fire from the bandicoot, drops it into the zamia plant where it ignites the highly flammable woolly kundyl. According to Noongar spokespersons, when we asked them about this myth, they said that the bright red seeds of the zamia give the illusion of fire. They all agreed that djiridji was probably a totemic name that may have been connected to this fire-retrieval story. We think that the term djiriji is a linguistic derivative of the term jir-e-git that was recorded by Grey (1840:55) as meaning “sparks” or by Moore (1842: 159) as girijit “sparks of fire.”
Macrozamia fruit are known as quinine or quenine in the southern region
In the southern region the Macrozamia fruit was commonly known as quinine or quenine (Barker 1830), also spelt gwineen (Grey 1840: 48), kween-een (Grey 1840:72), kwinin (Moore 1842: 64), quinning or quinelup, (A.Y. Hassell 1894). Grey (1840: 17, 22) also records the ‘boy’ at King George Sound as the equivalent of by-yu ‘the nut of the Zamia tree, when enveloped with pulp. Grey’s ‘boy’ may be viewed as synonymous with Salvado’s poio in the New Norcia region.
Barker, who was recording aspects of Aboriginal culture in the vicinity of King George Sound in 1830, was possibly the first European to record the fruit of the Zamia. He notes in his diary on January 9th 1830:
January 9 ‘Quinines not yet ripe.’
When exploring north of Cape d’Entrecasteaux and the Nornalup area, he writes:
‘This is the great country for ‘Quinine,’ the fruit of the low fan leaved palm which after gathering they bury in the earth for about a moon when it becomes fine eating. The country here is very populous and the people fat but he [Marignan] and others describe the soil to be poor & sandy.’ (7th June 1830)
On the following day Barker also writes:
‘This is the great country for Quenine, which after gathering, they bury in large store in the ground & in about a moon it becomes fine eating. This is the first instance of any provision of food which I have heard of them.’ (8th June 1830)
Barker’s (1830-1831) journal provides the earliest reference to the indigenous processing, storage and consumption of quinine (Macrozamia fruit) in southwestern Australia.
Noongar people ate only the processed sarcotesta, not the seed kernel
There is much confusion to this day, especially on the numerous “bush tucker” internet sources, as to which part of the Macrozamia fruit was consumed after processing by Noongar people. The traditional practice that is unique to southwestern Australia often gets confused with the methods used in Eastern Australia where only the starchy seed or endosperm was processed and eaten.
‘Macrozamia nuts leached and baked, were the carbohydrate staple all down the east coast of Australia’ (Rhys-Jones 1978).
In contrast the Noongar people of southwestern Australia consumed only the processed outer rind or seed covering known as the sarcotesta:
‘Only the fleshy part, which resembled a tomato in colour and taste, was eaten. The nut was not eaten.’ (Hammond 1933:28)
It is unclear from the ethnohistorical records when the Noongar stopped using this processed food source. The last recorded observation that we could find is by Edwards, a veterinary surgeon employed by the W.A. Bureau of Agriculture, who in 1894 reported that Noongar people were still processing Macrozamia fruit which they called boyah. He describes how during the fruiting season he observed seeds that were soaked “in shallow brooks” and also sometimes in bags ‘suspended by a string attached to a stake on the sea beach.’ Both Edwards (1894: 233) and Hammond (1933: 28) describe salt water being used in the preparation of boyah or boyoo. This practice is consistent with contemporary anecdotal accounts provided by informants of Macrozamia fruit having been soaked in water in wheat or chaff bags in the late 19th /early 20th century. According to one Noongar spokesman, Mr William Warrell, the “bo-yu” were placed in an old wheat sack with a few heavy rocks to weigh it down and a rope was then tied around the opening to ensure the seeds did not float away. The end of the rope was tied to a tree or stake to secure it. When we asked for how long this was done, he said he had no idea how long the seeds were left to soak, maybe about two weeks, he thought. He remembered being told this information by his grandmother Ollie Warrell who must have observed the activity when growing up.
Traditionally the ripe fruit were collected by Noongar women around March and transported in their goto (kangaroo skin bags) to the nearest processing location. These bases would have depended upon the availability of water which by the end of summer was mostly brackish or saline. Soaking pools were sometimes constructed on the edge of waterways but great care would have been taken not to contaminate the already limited drinkable water supplies. When water was scarce or not available the by-yu were buried for a number of weeks without soaking. These burial pits provided a form of hidden storage.
It was important that we reconstruct the method of how Macrozamia fruit was processed
In 2008 and 2009 we attempted to replicate traditional bayoo processing methods, in accordance with how they have been described in the ethnohistorical literature by Barker (1830), Moore (1835), Bunbury (1836), Drummond (1839), Grey (1840, 1841), Backhouse (1843) and Hammond (1933). The purpose was to gain an insight into how and why the fruit was soaked and/or buried for a certain period by Noongars prior to consumption. In 2009 the ChemCentre WA carried out an analysis of the sarcotesta prior to AND post-processing. The results of these tests are presented in a separate paper soon to be uploaded to this website.
Our archival research, practical experiments and consultations with Noongar Elders over a number of years together suggest that the Macrozamia fruit was processed using ancient indigenous cultural techniques and scientific knowledge to enhance the taste, texture and nutritional value and most importantly to enable the fruit to be easily removed from the seed. An added advantage may have been the ability to store and preserve this highly coveted food for a limited time.
To this day archaeologists, ecologists, historians and anthropologists maintain that Macrozamia sarcotesta was processed by Noongar people primarily for detoxification purposes. We would suggest that this assumption derives from the early reports of Europeans becoming violently ill from consuming unprocessed or insufficiently processed “Zamia nuts.” Moore (1835), Drummond (1839) and Grey (1840, 1841) all emphasise the need to detoxify the sarcotesta of the Macrozamia seed before consumption to avoid any ill-effects.
The earliest recorded account of European poisoning from the consumption of Macrozamia ‘nuts’ dates back to Vlamingh’s expedition in the Swan River area in 1697.
Prior to European colonisation of southwestern Australia the early Dutch explorers to the Swan River were experiencing first hand the ill-effects of consuming Macrozamia nuts. It is easy to imagine how these Dutch explorers assumed that these large “nuts” which to them resembled chestnuts (see Plate 9) and which they found lying around Aboriginal campsites were an edible food source consumed by the local inhabitants. We suspect that the Dutch were eating de-fleshed Zamia seeds left-over from a previous season. They describe them as a yellow-brown colour.
It is unlikely that the Dutch ever observed or consumed ripe Macrozamia fruit for at the time of their exploration of the Swan River area in early January 1697, these fruit would have been green, unripe, probably toxic and tightly compacted into the female cone or strobilus, as pictured below.
One of the Dutch officers describes in his diary how he and five other members of the Vlamingh expedition suffered the dire consequence of eating these fruits:
‘I ate five or six of them, drunk the water from one of the already mentioned pits [this is presumably a reference to a freshwater soak near the river]; but after about three hours I and five others who had eaten of these Fruits, began to vomit so violently that there was hardly any difference between us and death; so it was with the greatest difficulty that I with the Crew reached the shore… “(cited by Robert, 1972: 23)
Hamilton and Bruce (1998: 50) cite Witsen, one of the Vlamingh crew, as describing the Zamia fruit [Macrozamia of the Swan River region] as closely resembling:
‘…our local scarlet beans, the colour being between yellow and white: these beans contain a nut which is not unlike the chestnut and is not unappetizing, but causes a vertigo in the head which resembles madness, for the mariners who tasted of them crawled on the ground and made senseless gestures, which lasted for two days.’
We suggest that the nuts that the Dutch consumed may have been processed and discarded by the local indigenous inhabitants. These would have lost some of their toxicity through anthropogenic fermentation, natural ageing and weathering (see Plates 9 & 11). These combined processes may have accounted for the survival of the officer who consumed 5-6 nuts. The explorers would have been totally unaware that the nuts were not consumed by the indigenous inhabitants because of their toxicity. The Dutch described the roasted Macrozamia nuts ‘as tasting like Dutch broad beans, or, when less ripe [sic.], like hazelnuts’ (Playford 1998: 36).
When we showed a senior Noongar spokesperson some old seeds lying on the ground he agreed that they looked like egg-shaped stones and he suggested that the ‘old people’ who traditionally discarded them as useless would have regarded them in a similar way.
Grey (1840) and Moore (1842) record the terms dyundo, wida and gargoin as referring to the stone or kernel of the “zamia.” We would suggest that d-yundo is a body part metaphor referring to the “bald” nut (de-fleshed seed without sarcotesta). See Grey (1840: 34 dyundo, bald).
Bussell (n.d.) records buoyer queaja as Zamia nuts. This is possibly another body part metaphor signifying ‘flesh and bone’ (buoyer fruit or flesh + queaja/ kweitch, bone).
The Scottish botanist Robert Brown who accompanied Matthew Flinders aboard the Investigator visiting the south coast of Western Australia in 1802, records how he consumed 16 nuts of Zamia without any ill-effects. However, he highlights that other members of the crew were not so lucky. They suffered the punishing effects of zamia poisoning, which he describes as follows:
“sickness & retching [and] headache. In some the sickness came on [after] about an hour or two. In others it did not intervene for several hours. Mr Bauer felt only a Rise of Curd at his stomach all day but about 10 at night he was attacked with sickness which lasted till 2 in the morning.’ (Short 2002: 15-16)
Is it a coincidence that Brown acknowledges in his diary that he happened to be reading Henry’s Epitome of Chemistry and Cook’s Third Voyage at the same time as he extravagantly boasts of his capacity to ingest numerous cycad nuts without any adverse effect? Being a renown botanist he would have been familiar with the reference to Cook’s crew having suffered severely from cycad poisoning when visiting northeastern Australia in 1770.
What is the probability that almost forty years later the young explorer George Grey (1841:295-6) should also be reading Cook’s Voyage (Vol 2, page 624) and quoting from it around the time when his own men (like those of Cook and Brown) suffered violent bouts of sickness after consuming a store of Macrozamia nuts which they had found at an Aboriginal camp in the vicinity of the Gairdner Range in the Dandaragan region, north of Perth.
‘13th April 1839 – Kaiber here brought in some of the nuts of the Zamia tree; they were dry, and, therefore, in a fit state to eat. I accordingly shared them amongst the party. Several of the men then straggled off to look for more, and were imprudent enough, before I found out what they were doing, to eat several of the nuts which were not sufficiently dried, the consequences of which were, that they were seized with violent fits of vomiting, accompanied by vertigo, and other distressing symptoms; these, however, gradually abated during the night, and in the morning, although rendered more weak than they were before, the poor fellows were still able to resume their march.’ (Grey 1841: 61)
After suffering such traumatic consequences from eating what we suspect were either toxic Macrozamia kernels or rancid sarcotesta or simply over-indulging on this rich oily food, it is scarcely credible that the following day these same hungry and weakened men repeated the experiment of consuming Zamia nuts, this time without any reported ill-effects. Did Grey advise his men only to eat the processed sarcotesta and not the kernel, this second time round? Or was Grey trying to illustrate to his readers how dangerous this exotic food source was to the unsuspecting hungry settler or explorer? One of us wonders if this critical incident actually happened to Grey’s men or was it nothing more than a dramatic device to entertain his readers?
In his journal Grey (1841) quotes from Cook’s Voyage describing the cycad poisoning incident which involved a Cycas species (possibly Cycas media) – the nuts were:
‘…about the size of a large chestnut, but rounder. As the hulls of these were found scattered round the places where the Indians [Aborigines] had made their fires, it was taken for granted that they were fit to eat; however, those who made the experiment paid dear for their knowledge to the contrary, for they operated both as an emetic and cathartic, with great violence…
It is probable, however, that the poisonous quality of these nuts may lie in the juice, like that of the cassada [cassava] of the West Indies, and that the pulp, when dried, may be not only wholesome but nutritious.’ (Grey 1841 quoting from Cook’s Voyage).
We speculate that the substance of this extract from Captain Cook’s journal was to shape Grey’s views on the fundamental reason for the Noongar processing of Macrozamia sarcotesta in southwestern Australia. Soaking and burying the Macrozamia nut was believed to rid the “pulp” of its toxic qualities and dryness of the sarcotesta was considered the final hallmark of safety, thereby rendering it “nutritious”and edible.
Grey (1841: 296) categorically states that Macrozamia nuts were buried and
‘in about a fortnight the pulp which encases the nut becomes quite dry, and it is then fit to eat, but if eaten before that it produces the effects already described.’
It is not surprising that Grey adopts the same words “emetic and cathartic” to describe the harmful consequences of eating the unprocessed pulp.
‘by-yu: This name is applied to the pulp of the nut of a species of palm, which, in its natural state, acts as a most violent emetic and cathartic; the natives themselves consider it as a rank poison: they, however, are acquainted with a very artificial method of preparing it, by which it is completely deprived of its noxious qualities, and then becomes an agreeable and nutritious article of food.’
Grey points out, presumably on the basis of his own men’s adverse experience, that the Macrozamia kernel was toxic even after processing.
‘The process which these nuts undergo in the hands of the natives has no effect upon the kernel, which still acts both as a strong emetic and cathartic. ’ (Grey 1841: 297)
Ethnohistorical descriptions of how and why bayoo was processed
There are numerous accounts of European explorers (e.g. members of Vlamingh’s crew, Matthew Flinders’ party, Captain Fremantle’s party and Lieutenant George Grey’s men) all having suffered the ill-effects of cycad nut consumption in southwestern Australia. The accounts are often vague and difficult to interpret, although the nuts were generally found in the vicinity of Aboriginal camp sites, so it was assumed that the local indigenous inhabitants must have eaten them. The chestnut-like size and appearance of the de-fleshed Macrozamia nuts would have been too great a temptation to the hungry, unsuspecting European explorer. In most cases they were consuming the whole nut (including the kernel) not just the sarcotesta. There was a deeply entrenched colonial belief (promoted by Moore 1835 and Grey 1840, 1841) that the sarcotesta required detoxification through indigenous processing before it was edible. This assumption about ripe Macrozamia sarcotesta being toxic to humans unless having undergone extensive indigenous processing is still held to this day (see Meagher 1974; Smith 1982, 1992, 1999; Bindon 1996:173 and Asmussen 2011, 2012).
In this paper we do not question the toxicity of the de-fleshed Macrozamia seed (or “nut” as it is often called) for this has been scientifically well-established to contain harmful substances in particular cycasin and macrozamin. Aboriginal people in other parts of Australia always carefully processed the seeds using methods such as water-leaching and roasting prior to consumption of the starchy endosperm.
We question the view that has been promoted since the time of early settlement and still prevails in archaeological, ethnobotanical and ethnographic research papers that the Noongar processed the sarcotesta primarily for detoxification purposes.
As early as 1831 George Fletcher Moore writes:
‘The Zamia produces a sort of nut which the natives eat after considerable preparation by steeping in water but without this process it is said to be poisonous….’ (Moore 1831 in Cameron 2006: 14)
A few years later Moore (1835) describes eating some prepared baio after it had been processed:
‘Gigat invited us to eat some “Baio” along with him. The fruit, which is esteemed by them as a great delicacy, is the red skinned nut which is contained in the Fruit cone of the “Zamia.” The fleshy skin, for it scarcely can be called pulp, is the only part which is edible & even this is considered poisonous until it has been steeped so long in water, or buried in the earth, as to arrive at a state approaching decay. The flavor is something like that of medlar, or the taste of old cheese. Some of our party appeared to relish it but afterwards complained of its effects.’ (Moore 14th April 1835 in Schoobert 2005: 424)
It is clear from this description that Moore’s men were not suffering from cycad seed poisoning but rather we would suggest that their gut microbiome was ill-adapted to digest this rich fatty (and to them) alien food.
Moore’s original spelling of baio (1835) later changes to by-yu (1842) in accordance with George Grey’s spelling:
‘by-yu – The fruit of the zamia tree. This in its natural state is poisonous; but the natives, who are very fond of it, deprive it of its injurious qualities by soaking it in water for a few days, and then burying it in sand, where it is left until it is nearly dry, and is then fit to eat. They usually roast it, when it possesses a flavour not unlike a mealy chestnut; it is in full season in the month of May. It is almost the only thing at all approaching to a fruit which the country produces.’ (Moore 1842:24).
Grey (1841) describes the by-yu as follows:
‘No article of food used by the natives is more deserving of notice than the by-yu. This name is applied to the pulp of the nut of a species of palm, which, in its natural state, acts as a most violent emetic and cathartic; the natives themselves consider it as a rank poison: they, however, are acquainted with a very artificial method of preparing it, by which it is completely deprived of its noxious qualities, and then becomes an agreeable and nutritious article of food. Europeans who are not acquainted with this mode of preparing the nut, the stones of which they find lying about the fireplaces of the natives, are frequently tempted to eat it in its natural state, but they invariably pay a severe penalty for the mistake.’ (Grey 1841: 295)
Grey (1841) refers to the outer sarcotesta as the “pulp” of the nut whereas Moore (1835) asserts that the “fleshy skin” can hardly be called “pulp.” He refers to it as ‘the outer rind.’ Drummond (1862: 28) also refers to it as “rind.”
Salvado (1851 in Stormon 1977: 161) describes the Zamia nut or poio as having “no pulp” and comments:
‘The shell is red, and of fine texture, with no pulp. In order to make them fit for eating, the natives bury the flower [cone] together with the nuts for a certain time a couple of feet deep in the ground. The heat of the earth makes them swell as if to germinate a new plant, and they are then cooked on hot coals to form a substantial food with a pleasant taste.’
Drummond (1839) describes the “red-coloured arillus” as a favourite food of the natives.’ He writes:
‘…the fruit of the female palm is like a large pineapple. It contains many nuts about an inch long, covered with a red coloured arillus, which is a favourite food of the natives. To prepare the nuts and arillus for use, they steep them in water or bury them in the earth for some weeks, where they undergo a sort of fermentation and become wholesome food; when eaten without this preparation, they produce violent vomiting and other dangerous symptoms.’ (June 1839, in his Letter to Sir William Jackson Hooker, see p.18)
In 1842 Drummond observed that the large female “Zamia” cones:
‘contain numerous nuts, larger than a chestnut, and when ripe, they are covered with a beautiful red covering generally about two lines thick; this covering is a favourite food of the natives – they call the nuts “boyas.” Before they use the red covering of the nuts as food, they bury them in the ground for several weeks, or steep them in water, which has the same effect in a shorter time; when eaten without that preparation, they cause violent vomiting, and other distressing symptoms. The nuts, when deprived of their red covering, are not used by the natives as food (Drummond 1842 Letter No. 8, 28th September 1842).
Moore (1835), Drummond (1839) and Grey (1841, Vol 2: 296-297) all assume that indigenous processing of the Zamia nut took place to detoxify the pulp:
‘The native women collect the nuts from the palms [Macrozamia] in the month of March, and having placed them in some shallow pool of water, they leave them to soak for several days. When they have ascertained that the by-yu has been immersed in water for a sufficient time, they dig, in a dry sandy place, holes which they call mor-dak; these holes are about the depth that a person’s arms can reach, and one foot in diameter; they line them with rushes, and fill them up with the nuts, over which they sprinkle a little sand, and then cover the holes nicely over with the tops of the grass-tree; in about a fortnight the pulp which encases the nut becomes quite dry, and it is then fit to eat, but if eaten before that it produces the effects already described. The natives eat this pulp both raw [that is, processed but not roasted] and roasted; in the latter state they taste quite as well as a chestnut.’ (Grey 1841, Vol 2: 296)
Moore (1835) refers to the ‘fleshy skin’ as poisonous and Grey (1841: 295) states that the Aborigines themselves considered the pulp of the nut as ‘a rank poison.’ However, when Grey tried to inquire as to their reasons for processing it and the origin of this tradition, he could not get an answer that satisfied him. He states:
‘I have taken some trouble to ascertain if any traditional notion exists amongst the natives, which would in any way account for their having first obtained a knowledge of the means by which they could render the deleterious pulp of the Zamia nut a useful article of food; but in this, as in all other similar instances, they are very unwilling to confess their ignorance of a thing, and rather than do so, will often invent a tradition.’
It would seem that Grey did not understand their cultural explanation for why the by-yu was fermented. We would suspect that their explanation involved mythological metaphor rather than a scientific explanation that Grey was seeking. His view about the pulp being highly toxic and injurious to health may have derived from the experience of his own men and earlier explorer accounts combined with the popular colonial hearsay of the time. Perhaps his indigenous informants were not providing him with the information that he wanted to hear. Could we assume that his informants were providing him with an explanation that did not relate in any way to the extraction of toxins? It would seem that Grey (1841) trivialises what they are telling him, by pointing out to his readers ‘Hence many intelligent persons have raised most absurd theories, and have committed lamentable errors.’ In retrospect does Grey’s comment reflect on his own assumptions? We think that Grey’s informants may have been trying to explain to him that by-yu fermentation improved its taste and food value.
Bunbury (1836) and Backhouse (1843) do not mention toxicity at all in their accounts of bayoo processing
We find it surprising that Bunbury (1836) and Backhouse (1843) who would have been well-acquainted with the colonial comment of the time about the toxicity of this indigenous food without proper processing, do not mention detoxification as a reason for processing the sarcotesta prior to its ingestion.
Bunbury (1836) compares the two methods of indigenous processing and states:
‘The quickest method of ripening the Bayoo nuts is to bury them in a hole of water at the edge of a swamp or river when they become fit to eat in a few days but in this way they acquire a very strong bad smell & unpleasant taste, so I recommend all who are willing to wait a month for such delicacies, to bury them in the dry ground rather than in water.’ (Bunbury 1836 in Cameron and Barnes 2014:136)
Backhouse (1843) does not mention detoxification as a reason for processing Macrozamia sarcotesta but states with reference to the Perth area that:
‘…the Natives bury, or macerate, the nuts, till the rinds become half decomposed, in which state they eat the rind, rejecting the kernel; but in N.S.W., they pound and macerate the kernels, and then roast and eat, the rough paste.’ (1843:542).
Is Macrozamia sarcotesta toxic?
There are contradictions in the literature regarding the question of whether the sarcotesta of Macrozamia is toxic or not. Ladd (1993) in a one-off obscure study states that the sarcotesta of Macrozamia riedlei is ten times more toxic than the endosperm – a view that totally contradicts a 1938 study by the WA Government Chemical laboratories which showed the endosperm or kernel of Macrozamia fraseri to be highly toxic but the sarcotesta to be non-toxic.
We have long been confounded by Ladd’s (1993) results which not only contradict the WA Government Chemical laboratory findings but also defy cultural logic. Why would Noongar people eat the sarcotesta if it was so highly toxic and then discard the starchy kernel which according to Ladd’s study is less toxic? Asmussen (2011) seems to have accepted Ladd’s findings without question and formulates her discussion of Noongar processing on this premise. In doing this she further endorses the idea promoted by the early colonial writers, such as Grey (1840) and Moore (1842), that the sarcotesta of Macrozamia was processed by Noongar people for detoxification purposes. Asmussen states with reference to Ladd’s study:
‘Ladd et al.’s (1993: 39) research on the poisonous macrozamin content of a range of cycad species indicates that the Noongar people utilized the most toxic part of M. riedlei seeds, and discarded the least toxic part. The sarcotesta of M. riedlei contains a relatively high amount of macrozamin at 3.88% of fresh weight, comparable to that found in the kernels of M. miquelii and M. moorei (F. Muell)….’ (Asmussen 2011: 153).
She asks the same question that we have long puzzled over and asked ourselves, ever since reading Ladd’s study results:’
‘Why detoxify and consume the sarcotesta, which is the most toxic part of the resource?’ (Asmussen 2011:153)
If indeed the sarcotesta of Macrozamia reidlei is ten times more toxic than the endosperm, why has the ChemCentre WA not updated their records?
The ChemCentre was not aware of Macrozamia sarcotesta being toxic when we first asked them about it in 2008. In our own privately funded experiments we fed two white rats a diet of raw Macrozamia sarcotesta mixed with banana over a ten day period. Our results, like those of the Government Chemical Laboratories in 1938 which tested raw sarcotesta on guinea pigs, showed no adverse results. If anything our white rats thrived on this diet and looked very healthy. (See our forthcoming paper detailing our replicative Macrozamia processing experiments in 2009 and the results of tests conducted by the ChemCentre WA on the nutritional value of the sarcotesta before and after processing).
As far as we are aware there has been no other research carried out on the toxicity of the sarcotesta of Western Australian Macrozamia species. A compelling study by Hall and Walter (2014) which chemically tested the sarcotesta of Macrozamia miquelii from Eastern Australia found it to be non-toxic. They found no cycasin present in the “brightly coloured fleshy “fruit” of sarcotesta” and they proposed that the non-toxic Macrozamia sarcotesta was probably an ancient adaptation that served as ‘a reward for cycad seed dispersal fauna’ (2014: 860).
We believe that the bright red sarcotesta of Macrozamia fruit from southwestern Australia is also non-toxic and similarly functions as a “reward” for bird and animal seed dispersers. Why would a plant poison its own seed dispersal agents on which it relies for survival?
Hall and Walter (2013) write:
Globally, cycads are characterized by large, heavy seeds with an outermost fleshy layer (the sarcotesta) that on ripening develops vibrant colors…. Cycad seeds contain unique toxic compounds such as cycasin and macrozamin … However, the sarcotesta layer appears to be free of these poisonous compounds (Hall, 2011).’ (Walter and Hall 2013: 1127)5
It is our contention that the sarcotesta or outer fleshy “fruit” of the three species of Macrozamia found in southwestern Australia (M. fraseri, M. reidlei and M. dyeri) is also non-toxic at the time of full ripeness and when it releases a distinctive often pungent odour attracting seed dispersal agents, although it is highly possible that the unripe sarcotesta may contain toxins as part of the seed’s chemical armoury against herbivore predators. Hall and Walter’s (2014) analysis of the ripe sarcotesta of two cycads from Eastern Australia – including Macrozamia miquelii – showed that
“There is Toxic Cycasin in the Seeds of Cycads, but Not Their Sarcotesta “Fruit” ‘(Hall and Walter 2014: 862)
This is consistent with the findings of the WA Government Laboratories (1938-1939) which described the sarcotesta of Macrozamia fraseri as non-toxic.
Ripeness of the bayoo fruit
We cannot emphasise enough the importance of physiological ripeness when it comes to harvesting Noongar plant foods, most especially the bayoo. During the Macrozamia seeding season Noongar people were constantly aware of the different birds and animals that were drawn into the ecological food chain of predation on the ripening fruit. These were viewed as indicators that the fruit was ripe and ready for collecting and processing.
We have no doubt that toxins are present in the sarcotesta prior to ripening to protect the seed from herbivorous predators but once the fruit is physiologically ripe, turns a bright red colour and emits a distinctive odour, and the dehiscing fruit are exposed to natural elements in the external environment such as sunlight, we maintain that any toxins, if present, are reduced or eliminated. From our observations sunlight appears to be an essential ingredient in the ripening process.
Changes occur in the sarcotesta at the time the female cone disintegrates. Soon after exposure to sunlight (and possibly other factors such as moisture and humidity) the ripening fruit develops a distinctive odour attracting a host of insects, birds and animals that predate on the sarcotesta often leaving behind a trail of cleaned seeds and partially cleaned seeds under or in proximity to the female plant. The emu is one of the last surviving long distance Macrozamia seed dispersal agents.
The hovering hawk – a visible indicator of Macrozamia fruit ripeness
The Noongar could easily locate patches of ripening bayoo from a distance by the sight of hovering or circling birds of prey, such as the brown hawk (kargyne) or whistling kite (jandoo). These iconic avian predators were attracted to a rich food chain of smaller birds, reptiles, insects and marsupials that were magnetically attracted to the ripe fruit of the Macrozamia by its distinctive odour and bright red colour. Humans too were part of this complex food chain.
We explore the topic of bird and animal indicators of Macrozamia sarcotesta ripeness and the vectors of seed dispersal in a separate paper. Also. the results of our own practical reconstructive fermentation experiments and the food value analysis conducted by the ChemCentre WA of the sarcotesta before and after processing is soon to be uploaded to our website.
The taste of processed bayoo
We could find no agreement in the ethnohistorical literature on the taste of the fermented sarcotesta of Macrozamia. Whether this was due to a reluctance to taste it for fear of its toxicity or its unfamiliar and unappetising appeal to the Western palate is unclear. In 1835 Moore describes the flavour as:
‘something like that of medlar, or the taste of old cheese. Some of our party appeared to relish it but afterwards complained of its effects.’ (Moore 1835 in Schoobert 2005: 424)
At a later date Moore (1842: 23-24) describes the taste after being roasted as having ‘a flavour not unlike a mealy chestnut.’ This somewhat mirrors Grey’s description in his exploration journal (1841, Vol.2: 296) a year earlier where he comments that it tastes after roasting ‘quite as well as a chestnut.’ (Grey 1841, Vol 2: 296).
Bunbury (1836: 136) does not comment on taste, except to point out that the underground fermented bayoo have a much better taste than those soaked in water for only ‘a few days’ for the latter ‘acquire a very strong bad smell & unpleasant taste.’
Salvado (1851 in Stormon 1977: 161) describes poio as “pleasant” tasting:
‘…they are then cooked on hot coals to form a substantial food with a pleasant taste.’
Drummond (1862: 28), on the other hand, states:
‘To me it was disgusting, the taste being rancid, and resembling train oil’
Hammond (1933:28) describes boyoo after soaking in salt water as resembling ‘a tomato in colour and taste.’
Hassell (1975: 25) describes the taste and texture of quinine after being buried for a prolonged period as
‘soft and resembles a date but tastes very like an olive.’
Lyon (1833 in Green 1979: 168) describes a tasty treat in the form of a zamia fruit and frog cake. He states:
‘When the men return to the camp at night they are presented each with a cake by the women, apparently made of the fruit of the zamia and the flesh of frogs.‘
We suspect this cake was an oily mixture of the treated fruit of zamia squeezed together using the tips of the fingers with cooked frog meat.
The processed sarcotesta was either eaten raw or roasted. However, based on our own experience one has to be careful when cooking the sarcotesta not to lose the valuable oil. When one of us (Ken Macintyre) tasted processed (but unroasted) sarcotesta, he said:
It was a very rich and oily taste experience. It had the aroma of over-ripe Macrozamia fruit and the oily taste coated my palate after swallowing. It was not unlike my first experience tasting olive oil. To the Western palate Macrozamia sarcotesta would in my opinion be an acquired taste.’ (Ken Macintyre 2010).
Foods rich in fat will often absorb pungent esters during the fermentation process which add to their flavour and attractiveness to the human palate, like in the case of a matured stilton cheese. We would suggest that fermented bayoo underwent a similar transformation and that its resultant taste was culturally relished and sought-after as well as being highly nutritious. Bayoo were consumed during the season know by Noongar people as jeran. This term translates as “fat” (jerang, jerrung, cherung) and corresponds to the time of the year around autumn (late March/April/May) when it was mandatory for Noongar people to build up their reserves of sub-cutaneous body fat to ensure their survival through the long cold dark wet lean season of makuru (or mokkar at Albany). Fat-rich foods such as bayoo, bardi, kuya (frog) and kalda (mullet) were highly sought after at this time.
Archaeological Evidence of Macrozamia pits
The earliest archaeological evidence of indigenous Macrozamia seed processing in Australia derives from southwestern Australia where Smith (1982) located ancient Macrozamia kernels in what appears to be a shallow pit (20cm) that she suggests may have been used for water-leaching or fermentation pit purposes, dating back approximately 13,000 years BP. This early evidence of cycad processing at Cheetup rockshelter in the Esperance region during the late Pleistocene is about 9000 years earlier than the earliest recorded archaeological dates for cycad seed processing in Northern and Eastern Australia which date back to the recent Holocene period, approximately 4,300 years BP (Beaton 1982; Beck 1992).
It is possible that fermentation of Macrozamia fruit may have occurred within a shallow pit. However, based on our own practical experiments and reconstructive efforts of fermenting Macrozamia fruit in earth pits, we found that the shallow pits attracted fruit predation from insects (such as weevils) and domestic rats. We would suggest that the deeper pits – about an “arm’s length” depth as recorded by Grey (1840, 1841) – would have afforded a number of advantages including a constant anaerobic and thermogenic environment for fermentation to take place and protection against insect and small burrowing-animal predation. Grey (1840, 1841) records the depth (mordak) of traditional Macrozamia fruit fermentation pits as an “arm’s length” and we would suggest that it was a woman’s arm length (possibly about 60cm). Depth of pit was important to protect the fermenting fruit from human and non-human predators. The soil digging habits of the kwenda (short nosed bandicoot) -which according to some Elders is a sarcotesta eater – may explain the reason why the fermentation pits were so deep – to prevent these valuable stores of food being raided by digging marsupials.
Ownership rights over the by-yu fruit
We are told that Grey’s indigenous guide Kaiber discovered four “holes” of stored Zamia nuts known as by-yu and that he came to request ‘permission’ from Grey ‘to steal them’ (1841, Vol 2: 64). Grey translates Kaiber’s comments as follows:
’14th April – If we take all, this people will be angered greatly; they will say, ‘What thief has stolen here: track his footsteps, spear him through the heart; wherefore has he stolen our hidden food?’ But is we take what is buried in one hole, they will say – ‘Hungry people have been here; they were very empty, and now their bellies are full; they may be sorcerers; now they will not eat us as we sleep’ (Grey 1841, Vol 2: 64-65).
‘Good- it is good Kaiber,” I replied; “come with me, and we will rob one hole;” and accordingly we went and took the contents of one, leaving three others undisturbed. I brought back these nuts to the men, and we shared them amongst us.’ (Grey 1841, Vol 2: 65).
Grey (1840: 48), referring to the King George Sound area, records gwin-een as ‘the common stock of food.’
The name quinene or quinine was first recorded for this food in 1830 by Captain Collett Barker who was told by his Aboriginal guide and informant Mokare that:
‘the provision of Quinene is made by everyone, but is often stolen. Generally speaking the owners are not sulky at this, it not being considered so sacred a property as Spears, Kangaroo, Wallabi,etc, or even grass trees, but he recollects hearing of one man speared on account of it.’
Bunbury (1836 in Cameron 2014:136), when exploring the Perth to Pinjarra region, refers to the bayoo:
‘The Zamia plants are considered private property by the natives who do not consider it right to gather Bayoo belonging to others, though they do not scruple to catch and eat any animals, birds or reptiles, they may meet with in their passage through the lands or buggia [i.e. boodjor, land, country] of other tribes. ‘
What Bunbury did not realise when making these statements was that he was demonstrating the difference between certain carefully managed bio-cultural resources (such as the Zamia, grass tree, kangaroo and wallabi) whereas the others were a composite of common property.
The quinine trade
Ethel Hassell, who was recording her observations of Aboriginal culture in the 1880’s at Jerramongup, refers to the trading of processed Macrozamia sarcotesta known as quinine from the coast to inland areas where the Macrozamia did not grow. She gives little detail on the trading relationship that took place, other than a description of how the quinine was prepared. She comments that:
‘For trading, the natives take the stone out, which are never eaten, as they retain the poison, and string the fruit on rushes. They never lose their red colour or shiny look, and keep good for quite a long time (Hassell 1974: 25).
Stringing the fruit on rushes would have facilitated portability, preservation and storage of this much coveted food. With our own reconstructive experiments we found that the processed and preserved sarcotesta fruit retained its colour, odour and most of its food value after being kept for 12 months in a dry, airtight environment (see photo below). Tests conducted by the ChemCentre WA verified its high food value after 12 months. See forthcoming paper soon to be uploaded to this website.
It is a pity that Hassell does not provide any further details on this unique trade and we wonder if it only occurred in the southern region? Also, what did the inland Wheelman people provide in exchange for this relished comestible from the coast? What were the trading relationships between these groups and how was this surplus of Macrozamia sarcotesta obtained? Was there some form of active cultivation taking place? Did this preserved oily fruit have a ritual value?
It is not uncommon throughout the world for indigenous peoples to process and preserve food in different ways through soaking, salting, drying and fermenting to enhance the taste, texture and nutrient value of the food. Archaeological evidence suggests that the Noongar people of southwestern Australia practised a unique method of pit fermentation that increased the nutrient value of cycad sarcotesta at least 13,000 years ago during the late Pleistocene. This would have to be one of the earliest methods of food fermentation recorded in the world. The Noongar are the only documented group in Australia to traditionally consume Macrozamia sarcotesta prepared by means of anaerobic fermentation.
In this paper we have questioned the observations and assumptions of Grey (1839), Moore (1842) and Drummond (1842) that the sarcotesta of Macrozamia seed was processed primarily to rid it of its toxic properties.
Grey’s (1842) wordlists and his often-quoted exploration journals profoundly influenced colonial hearsay and even to this day continue to provide a pivotal reference for researchers wishing to gain insights into aspects of traditional Noongar culture. However, we challenge his theory that the by-yu or Macrozamia ‘pulp” (thin fleshy outer layer) was processed by indigenous people primarily for the purpose of detoxification. Instead we argue that the ripe sarcotesta was processed to improve the taste, nutritional content and to facilitate its removal from the seed which was discarded. Soaking and/or anaerobic fermentation may have also played a part in extending the seasonal shelf life of the fruit which in some parts of the country was used as an article of trade.
Throughout this paper we have been frustrated by the lack of scientific analysis and/or updated records at the ChemCentre WA and relevant government departments concerning the question of the toxicity of the sarcotesta of local species of Macrozamia. As far as we are aware there have been no studies conducted since the Government Chemical Laboratory findings in 1938-1939 which determined the sarcotesta of Macrozamia fraseri to be non-toxic. There has only been one little-known study by Ladd et al (1993) which contradicts the earlier findings of the WA Government Chemical Laboratory. Ladd’s paper which highlights the toxicity of Macrozamia sarcotesta was prepared as a conference paper and to our knowledge has not been followed up with any replicative studies or further publications which consolidate his initial findings. We do not understand why such a supposedly dangerous and toxic neuro-chemical such as macrozamin has not been thoroughly studied in the sarcotesta of the commonly occurring fruit/seed of local species of Macrozamia found in bushland.
We strongly recommend that further research and chemical analysis be carried out using ripe sarcotesta of local Macrozamia species to establish once and for all whether this red outer layer of the seed is harmful to humans.
We caution readers not to experiment with consuming any part of the Macrozamia seed or sarcotesta for safety purposes. The seed is known to contain toxins while the toxicity of the sarcotesta has not yet been definitively assessed.