Overall Nutritional and Sensory Profile of Different Species of Australian Wattle Seeds (Acacia spp.): Potential Food Sources in the Arid Semi-Arid Regions

Food Choices, Sustainability and Australian Native Foods: Perceptions among University Students

(1) Background: Urgent changes in our food choices are needed for more sustainable, resilient and equitable food systems. Australian native plant-based foods have both environmental and health benefits. Including these foods in our diet may reduce both the risk of chronic diseases and the impact of climate change. This study explored the perceptions and attitudes towards food choices, sustainability and Australian native plant-based food among university students. (2) Methods: A cross-sectional online survey was completed by 212 university students in Australia from October to December 2022. Questions included information about sociodemographic characteristics, food choices, Australian native foods and the impact on sustainability. Logistic regression was used for analyses. (3) Results: Most participants recognised the impact of food choices on sustainability. There was a significant association between recognition of the impact of food choices on sustainability and the environmental and nutritional benefits of Australian native foods (OR = 2.89, 95% CI 1.29, 6.46, p = 0.010). Students who were familiar with or had tried Australian native plant-based foods were significantly more likely to recognise their environmental and nutritional benefits (p < 0.001). (4) Conclusions: Students who recognise the impact of food choices on sustainability and the benefits of Australian native foods are more likely to include native foods in their diet. More studies are needed to investigate the specific native foods consumed and the barriers and facilitators to the intake of these foods.

Non-Sensory Perception and Sensory Appeal of Zamnè, PseudoZamnè, Traditionally Cooked Senegalia erythrocalyx Seeds, and Tempeh According to Burkinabe Consumers

The lack of adequate knowledge of the culinary and sensory properties of most indigenous and wild foods hampers their promotion in human diets and the market. In the present study, 80 Burkinabe volunteers evaluated the sensory appeal and attributes of three selected Senegalia seed species (Zamnè, pseudoZamnè or Kumatiya, and S. erythrocalyx) and their food formulae (traditionally cooked, harvested as green and fresh legumes, and fermented as tempeh) using the nine-point hedonic scale and check-all-that-apply questionnaire. They found that the traditionally cooked Zamnè, pseudoZamnè or Kumatiya, and derived tempeh had good sensory appeal (scoring between 5 and 7) and subtle alkaline and nutty tastes. However, an appreciable number (32%) of the participants were unaccustomed to tempeh and gave very low scores (2.5-3.4) for all the tempeh products. In contrast, the traditionally cooked seeds of Senegalia erythrocalyx and the green and fresh Zamnè evoked bitter and sour off-tastes, respectively, and were not much appreciated (scoring 4). The present study provides unprecedented insight into consumers' non-sensory perceptions and the culinary and sensory properties of Senegalia seed foods, which will be essential for their valorization, branding, and marketing.

Antioxidant activities, phenolic compounds, and mineral composition of seed from Acacia retinodes, A. Provincialis and A. Tenuissima

Seeds of the species Acacia retinodes, A. provincialis, and A. tenuissima) from different growing locations were analysed for their mineral composition, free and bound polyphenols, and flavonoids. Previous research has studied these compounds in only a limited number of Acacia species, and only one study reports significant differences between three species. All species were rich in potassium (353 - 427 mg/100 g), sodium (14 - 240 mg/100 g) and iron (7 - 8 mg/100 g). The free polyphenol extracts of all species had higher total phenolic content, total flavonoid content and antioxidant activities than their bound counterparts, indicating the possibility of higher bioavailability than the bound polyphenol extracts. The predominant phenolic compounds found in the Acacia polyphenol seed extracts were 6-Hydroxy-2-methylindole and 2,2'-Methylenebis(6-tert-butyl-methylphenol), though no phenolic compounds were identified in the bound extracts of A. retinodes Grampians and A. provincialis Tarrington. Other compounds identified in the seed extracts include sucrose, d-fructofuranose and d-pinitol.

Effects of incorporating processed Acacia seed as an emulsifying agent on the quality attributes of beef sausage

In this study, partial or full replacement of 6% soy protein isolate (SPI) with 2, 4 and 6% roasted Acacia seed flour (ASRo) and Acacia seed protein concentrates (ASPC) in emulsified beef sausage were investigated. Emulsion stability and cooking loss were lower in samples formulated with ASPC at all levels and control samples compared to ASRo formulated samples. ASRo generated softer and less chewy sausages than ASPC. Cooked 2% ASPC sausages had similar L* and a* values as the control but with lower colour difference (ΔE) values that were similar to cooked 6% SPI sausages' values. An organized protein network structure was observed in the sausages formulated with ASPC at all levels and in the control samples. Therefore, ASPC, particularly at 2 and 4% inclusion, can be used as a functional ingredient to prepare emulsified beef sausages with good quality attributes.

Quality Assessment of Burdekin Plum (Pleiogynium timoriense) during Ambient Storage

Pleiogynium timoriense, commonly known as Burdekin plum (BP), is among many Australian native plants traditionally used by Indigenous people. However, only limited information is available on the nutritional and sensory quality of BP grown in Australia as well as its changes during storage. Therefore, this study evaluated the quality of BP during one week of ambient storage (temperature 21 °C, humidity 69%). Proximate analysis revealed a relatively high dietary fiber content in BP (7-10 g/100 g FW). A significant reduction in fruit weight and firmness (15-30% and 60-90%, respectively) with distinguishable changes in flesh color (ΔE > 3) and an increase in total soluble solids (from 11 to 21 °Brix) could be observed during storage. The vitamin C and folate contents in BP ranged from 29 to 59 mg/100g FW and 0.3 to 5.9 μg/100g FW, respectively, after harvesting. A total phenolic content of up to 20 mg GAE/g FW and ferric reducing antioxidant power of up to 400 μmol Fe²⁺/g FW in BP indicate a strong antioxidant capacity. In total, 34 individual phenolic compounds were tentatively identified in BP including cyanidin 3-galactoside, ellagic acid and gallotannins as the main phenolics. Principle component analysis (PCA) of the quantified phenolics indicated that tree to tree variation had a bigger impact on the phenolic composition of BP than ambient storage. Sensory evaluation also revealed the diversity in aroma, appearance, texture, flavor and aftertaste of BP. The results of this study provide crucial information for consumers, growers and food processors.

Compositional and functional changes in Acacia tenuissima seeds due to processing

The chemical, functional, anti-nutritional, and antioxidant composition of raw and roasted Acacia tenuissima seeds were determined to evaluate the impact of heat processing. The raw seeds were relatively high in protein (25.2 %), fat (10.3 %) and crude fiber (13.2 %), potassium (760 mg/100 g), magnesium (111 mg/100 g) and calcium (66.5 mg/100 g). Linolenic (34 %), margaric acid (24 %) and oleic acid (16 %) were the notable fatty acids present in the raw seeds. The proximate and fatty acid composition of A. tenuissima were not significantly impacted by roasting. Acacia tenuissima flour had excellent foaming capacity, foaming stability and water solubility making it a potential functional ingredient in the baking industry. Anti-nutrients were present in the raw seeds but at low quantities (trypsin inhibitor activity: 0.22 TIU/g, saponin: 2.29 %) while the antioxidant activity was high at 94 % compared to other Acacia species. Only the water solubility and trypsin inhibitor activity of A. tenuissima decreased significantly after roasting. Roasting had no significant impact on the seed constituents and their properties except for water solubility, and trypsin inhibitor activity which decreased, making it an ideal ingredient to be used in baked products.

Nutritional and techno-functional properties of Australian Acacia seed flour: Effects of roasting on chemical composition, physicochemical properties, and in vitro digestibility and intestinal iron absorption

Acacia seed (AS) is rich in protein and iron but contains protease inhibitors that can reduce protein digestibility (PD). The seeds are generally roasted prior to consumption, although no information on the PD of roasted AS is available. This study investigated the effect of roasting time (5, 7 and 9 min at 180 °C) on the chemical composition, physicochemical properties, and in vitro PD and intestinal iron absorption of three wild harvested Australian AS species, Acacia victoriae, A. coriacea and A. cowleana. Roasting A. victoriae and A. coriacea seeds for 7 min significantly increased PD in the seeds by 36 and 61 %, respectively. A 9-min roasting time was required to achieve 75 % reduction in trypsin inhibitor activity in A. coriacea seed, while a shorter roasting time (RT) was sufficient to achieve similar reduction rates in the other two Acacia species. Among the functional properties, water and oil absorption capacities were significantly enhanced as RT increased. The starch granules in 7- and 9-min roasted A. victoriae seed flour detached from the protein matrix while random coil increased in 7-min roasted A. victoriae and 9-min roasted A. coriacea and A. cowleana, thus, contributing to enhanced PD. Although the SDS-PAGE in 7- and 9-min roasted A. cowleana samples showed reductions in the intensity of bands for high molecular weight proteins, PD was not affected by RT. However, intestinal iron absorption was not significantly affected by roasting as compared to raw digesta samples. Compared to commercial roasted Acacia seed, the considerably shorter RT used in this study improved PD in the AS flour with less adverse effects on techno-functional properties.

The Framework for Responsible Research With Australian Native Plant Foods: A Food Chemist's Perspective

Australia is a rich source of biodiverse native plants that are mostly unstudied by western food science despite many of them being ethnofoods of Australian Indigenous people. Finding and understanding the relevant policy and legal requirements to scientifically assess these plants in a responsible way is a major challenge for food scientists. This work aims to give an overview of what the legal and policy framework is in relation to food chemistry on Australian native plant foods, to clarify the relationships between the guidelines, laws, policies and ethics and to discuss some of the challenges they present in food chemistry. This work provides the framework of Indigenous rights, international treaties, federal and state laws and ethical guidelines including key legislation and guidelines. It discusses the specific areas that are applicable to food chemistry: the collection of plant foods, the analysis of the samples and working with Indigenous communities. This brief perspective presents a framework that can be utilized by food chemists when developing responsible research involving plant foods native to northern Australia and can help them understand some of the complexity of working in this research area.

Nutritional, anti-nutritional, antioxidant, physicochemical and functional characterization of Australian acacia seed: effect of species and regions

BACKGROUND

Acacia seed (AS) is an underutilized legume widely distributed in the world, with majority of the species (>70%) found in Australia. Generally, the seeds are not only rich in protein, dietary fibre and potassium, but also possess anti-nutritional compounds. In recent years, there have been an increase in the cultivation of some Australian acacia species such as Acacia victoriae, Acacia cowleana and Acacia coriacea from different regions. However, there is limited information on the composition, anti-nutrients, antioxidant and functional properties of flour from these widely grown Australian AS species. Thus, the present study aimed to assess the properties of these Australian AS species from different geographical regions.

RESULTS

The A. cowleana and A. coriacea were characterized by high protein, fat, potassium and soluble carbohydrate. However, higher starch and fibre contents were present in A. victoriae. Greater amounts of anti-nutrients, total phenolics and flavonoids were found in A. cowleana and A. coriacea seeds, whereas A. victoriae had higher 2,2-diphenyl-1-picrylhydrazyl radical-scavenging capacity. A. victoriae and A. coriacea demonstrated the highest water absorption and solubility index, respectively. However, A. cowleana showed the highest oil absorption index. There was less variation in the composition and properties within species from different regions.

CONCLUSION

All samples showed promising nutritional characteristics, although with sufficient diversity to indicate that Australian acacia seeds can be utilized to develop a range of new (functional) food products. Overall, the information obtained will help the food industries with the selection of AS species for food application.

Mid-Infrared Spectroscopy as a Rapid Tool to Qualitatively Predict the Effects of Species, Regions and Roasting on the Nutritional Composition of Australian Acacia Seed Species

In recent times, the popularity of adding value to under-utilized legumes have increased to enhance their use for human consumption. Acacia seed (AS) is an underutilized legume with over 40 edible species found in Australia. The study aimed to qualitatively characterize the chemical composition of 14 common edible AS species from 27 regions in Australia using mid-infrared (MIR) spectroscopy as a rapid tool. Raw and roasted (180 °C, 5, 7, and 9 min) AS flour were analysed using MIR spectroscopy. The wavenumbers (1045 cm⁻¹, 1641 cm⁻¹, and 2852–2926 cm⁻¹) in the MIR spectra show the main components in the AS samples. Principal component analysis (PCA) of the MIR data displayed the clustering of samples according to species and roasting treatment. However, regional differences within the same AS species have less of an effect on the components, as shown in the PCA plot. Statistical analysis of absorbance at specific wavenumbers showed that roasting significantly (p < 0.05) reduced the compositions of some of the AS species. The results provided a foundation for hypothesizing the compositional similarity and/or differences among AS species before and after roasting.

The use of Australian native grains as a food: a review of research in a global grains context

Australian native grains have an extended history of human consumption; however, their place in diets was disrupted when colonisation triggered a shift away from traditional lifestyles for Aboriginal people. Despite being time- and energy-intensive to harvest, the inclusion of native grains in diets is thought to have offered considerable adaptive advantage by assisting human occupation of arid and semiarid zones. Ethnographic evidence has shown that Aboriginal people developed specialised tools and techniques to transform grain into more edible forms. Research on native grain consumption has mainly been conducted from an ethnographic perspective, with the objective of furthering understanding of Aboriginal societies, instead of the agricultural or food science significance of these plant species. Consequently, a research gap in all aspects of Australian native grains in modern food-production systems from the paddock to plate has emerged, and is being filled by research projects in multiple parts of the country due to surging interest in this food system. There is a critical need for Aboriginal communities, land managers, food industry professionals and research institutions to come together and set a research agenda that ensures cultural protocols are respected, research investment is not unnecessarily duplicated, and the results are targeted to places where they will be of most benefit to people and the planet.

Insights for the Valorization of Biomass from Portuguese Invasive Acacia spp. in a Biorefinery Perspective

Acacia spp. are widespread all over the Portuguese territory, representing a threat to local biodiversity and to the productivity of the forest sector. The measures adopted in some countries for their eradication or to control their propagation are expensive, have been considered unfeasible from practical and economical perspectives, and have generated large amounts of residue that must be valorized in a sustainable way. This review brings together information on the valorization of bark, wood, leaves, flowers, pods, seeds, roots, and exudates from Acacia spp., through the production of high-value bioactive extracts (e.g., antioxidant, antimicrobial, anti-inflammatory, antidiabetic, antiviral, anthelmintic, or pesticidal agents, suitable to be explored by pharmaceutical, nutraceutical, cosmetics, and food and feed industries), its incorporation in innovative materials (e.g., polymers and composites, nanomaterials, low-cost adsorbents), as well as through the application of advanced thermochemical processes (e.g., flash pyrolysis) and pre-treatments to decompose biomass in its structural components, regarding the production of biofuels along with valuable chemicals derived from cellulose, hemicellulose, and lignin. The knowledge of this research is important to encourage an efficient and sustainable valorization of Acacia spp. within a biorefinery concept, which can bring a significant economic return from the valorization of these residues, simultaneously contributing to forest cleaning and management, to reduce the risk of fires, and to improve the social-economic development of rural areas.

Introduction to the Special Issue: Legumes as Food Ingredient: Characterization, Processing, and Applications

Legumes are major ingredients in the Mediterranean diet, playing an essential role in developing countries. Grain legumes, such as lentil, chickpea, pea, lupin and beans, among others, are recognized as good sources of proteins, starch, fiber, vitamins and minerals for human nutrition, being an essential food crop for people worldwide. Due to their nutritional and techno-functional properties, legumes are widely used by the food industry as ingredients in a wide range of products for general and specific groups of the population, including vegetarians, diabetics or celiac patients. The Special Issue “Legumes as Food Ingredients: Characterization, Processing, and Applications” covers key aspects regarding the nutritional quality of legume flours and their derived products, as well as the health benefits of some of their bioactive components. The amounts of antinutritional components, such as certain allergens that might pose risks to sensitized consumers, are reported to be reduced by processing. Several pretreatments, including fermentation with lactic bacteria and yeasts, are used to improve the nutritional and sensory profile of the legume-derived products, increasing their acceptance by consumers.