50 plant species from the Indigenous Food Database with high nutritional profiles and/or highly prospective in terms of taste and flavour were assessed, along with their optimal preparation and cooking requirements, to identify potential superfoods.
Moreton Bay fig shoots and mangrove seeds have been identified as traditional foods used in modern cuisine. The traditional processing method for these foods involves their treatment in ash water to remove bitterness and render the shoots/seeds palatable.
Ash analysis suggested that the ash produced by the Restaurant Orana chefs is non-porous, i.e. it has no internal capacity to absorb chemical compounds, as would typically occur with commercial absorbents (e.g. activated carbon). pH measurements demonstrated that ash is highly alkaline. Consequently, when the ash is added to water, it produces a highly alkaline mixture, which potentially has some capability to adsorb organic compounds, and it was concluded that the ash plays a role in absorbing the organic compounds that were extracted from the fig shoots
An alternate method of treating fig shoots was developed, which involves using a reduced volume of ash for extraction, based on pH testing of ash samples, and soaking the fig shoots in ash water prior to pressure cooking. Shoots were then placed in apple cider vinegar overnight, brined (in cryo-vac bags) and refrigerated for 6 weeks. Microbiological testing confirmed there was no apparent microbial spoilage. Mangrove seeds were also subsequently processed using this optimised method.
A blind tasting of fig shoots and mangrove seeds produced by the Restaurant Orana chefs vs. the alternate process developed during the project was conducted. Overall, bitterness was rated lower for fig shoot made using the new production process but only slightly. Descriptors included a slightly wider range of aroma and flavour attributes, such as chocolate, confectionary, pine, dried fruit and allspice, in addition to the descriptors used for the Restaurant Orana chef-processed fig shoots, which included woody, earthy, vegetal, peppermint, salty and wet hay. The Restaurant Orana chef shoots were considered to have a stronger vinegar/sour flavour/taste, which may have masked other attributes. Liking scales for the fig shoots produced using the Restaurant Orana chef method vs. the alternate method were very similar at 4.7 and 4.5/10, respectively.
Significant differences were reported for the sensory properties of mangrove seeds processed by the Restaurant Orana chefs vs. the alternate method. In general, the Restaurant Orana seeds were rated more favourably on the liking scale (4.6 and 5.3 respectively). The mangrove seeds produced via the alternate method were described as fishy, earthy, musty, vegetal and savoury, whereas the Restaurant Orana chef-prepared seeds were described as floral, fruity, green tea, vegetal, spiced and smoky. The mangrove seeds processed via the alternate method were described as more intact than the Restaurant Orana chef-prepared seeds
Yeast and bacteria present in Restaurant Orana chef-prepared fermented foods were identified. Whilst the fermented products varied significantly, the yeasts were common amongst all. The bacteria were all from the bacillus family and a brief literature search showed none to be known human pathogens. This suggest that much of the fermentation process taking place in the restaurant are lactic acid ferments, giving these foods a “vinegary” flavour
The yeast isolates were fermented individually in apple juice, honey or blackberry juice. The blackberry juice ferments had the most interesting aromas, seemingly because of the more complex and fruity aromas of the original fermentation media.
A few additional native food fermentations were produced at a laboratory scale. Strawberry gum tea leaves steeped in water were used as a base for a cordial-like beverage produced similarly to ginger beer. A natural ferment, steeping Hakea spp. flowers in water and allowing the naturally present yeasts to ferment the liquid, was also attempted. The resulting product had a distinct umami flavour with a salty, olive aftertaste. The yeasts and bacteria responsible for this fermentation have been isolated for identification. Finally a ferment using Nitraria billardiera, which produced a product similar in taste and aroma to soy sauce.