Effect of processing on proximate composition, anti-nutrient status and amino acid content in three accessions of African locust bean (Parkia biglobosa(jacq.) benth

Protein Quality of African Locust Bean-A High-Value Gathered Tree Food Contributing Protein and Palatability to Plant-Based Diets

The African locust bean tree Parkia biglobosa (Jacq.) R.Br. ex G. Don is a leguminous species native to the Sudanian parkland of western Africa. The seed obtained from pods collected from trees by rural women is fermented into a dense and aromatic paste known as soumbala, dawadawa, or iru-a protein-rich condiment underlying much of West African cuisine, its rich umami base lending a depth of flavor as a "meat substitute" in plant-based diets for which animal protein is a limiting component. Here, we assess the protein quality of P. biglobosa seed and its fermented product (soumbala) from three locations of southern Mali comprising three different eco-climatic zones, to determine whether variation in nutritional composition and protein quality could be correlated with the geographic variables of latitude and elevation. Proximate composition was determined, and amino acid profiles were compiled for 19 amino acids, with results compared by location and eco-climatic zone. A protein quality test was conducted in the aggregate and for each zone using the WHO/FAO Protein Digestibility-Corrected Amino Acid Score (PDCAAS) method. Principal component analysis (PCA) was used to assess patterns of amino acid compositional variation between the three origins. The results underline the nutritional significance of African locust bean as a source of dietary protein and of a depth of flavor providing enhanced palatability to plant-based diets. Although the PCA biplot for the amino acid profiles does indicate geographic clustering, the variation in nutritional composition and protein quality is insignificant for the raw seed, but highly significant for the fermented product (soumbala). The results indicate no correlation between phytochemical parameters and geographic variables of latitude and elevation, suggesting that management and processing may contribute more to nutritional quality than product provenance. Further studies should assess specific processing methods and the ambient microbiome as factors contributing to protein quality.

Plant-Based Alkaline Fermented Foods as Sustainable Sources of Nutrients and Health-Promoting Bioactive Compounds

Traditional food fermentation is a practice that precedes human history. Acidic products such as yogurts and sourdoughs or alcoholic beverages produced through lactic acid or yeast fermentations, respectively, are widely described and documented. However, a relatively less popular group of fermented products known as alkaline fermented foods are common traditional products in Africa and Asia. These products are so called “alkaline” because the pH tends to increase during fermentation due to the formation of ammonia resulting from protein degradation by Bacillus species. Plant-based alkaline fermented foods (AFFs) are generally produced from legumes including soybean, non-soybean leguminous seeds, and other non-legume plant raw materials. Alkaline fermented food products such as natto, douchi, kinema, doenjang, chongkukjang, thua nao, meitauza, yandou, dawadawa/iru, ugba, kawal, okpehe, otiru, oso, ogiri, bikalga, maari/tayohounta, ntoba mbodi, cabuk, and owoh are produced at small industrial scale or household levels and widely consumed in Asia and Africa where they provide essential nutrients and health-promoting bioactive compounds for the population. Alkaline food fermentation is important for sustainable food security as it contributes to traditional dietary diversity, significantly reduces antinutritional components in raw plant materials thereby improving digestibility, improves health via the production of vitamins, and may confer probiotic and post-biotic effects onto consumers. In this review, we present currently available scientific information on plant-based AFFs and their role as sustainable sources of nutrients and bioactive compounds for improved health. Finally, we provide perspectives on research needs required to harness the full potential of AFFs in contributing to nutrition and health.

Nutrient composition of Parkia biglobosa pulp, raw and fermented seeds: a systematic review

There is increasing evidence that nutrient differences observed among crop varieties or animal breeds belonging to the same species are sometimes greater than differences between species. Parkia biglobosa is an important tree species that provides edible products and income to rural households in West Africa. To better understand intra-species nutrient variability of P. biglobosa edible products, a review on the nutrient content of its pulp and seeds (raw and fermented) was conducted. Google scholar and the keywords "P. biglobosa" AND "nutrition" were used to screen the available literature from 1980 onwards, and the Zotero software was used to manage references. A step-wise assessment of titles, abstracts and full papers, led to a selection of 69 papers from which data were retrieved following FAO INFOODS guidelines. After data harmonization and quality checks, 42 papers were retained and used to extract data to populate a nutrient database. Despite an apparent abundance of nutrient analyses focused on P. biglobosa's edible products, the quality of data available was poor and very few authors presented additional information, such as soil characteristics, climate, maturity at harvest, etc. that could influence the nutritional content of the products. Many data gaps remain. The present study will stimulate further investigations into nutrient composition of P. biglobosa products and ultimately will contribute to selecting nutritionally "+" trees for multiplication and/or domestication of the species.

Effect of processing methods on compositional evaluation of underutilized legume, Parkia roxburghii G. Don (yongchak) seeds

The present study has been undertaken to analyze the effect of various processing methods like (i) soaking followed by autoclaving with (a) ash, (b) sodium bicarbonate, (c) sugar and (d) water; (ii) dry heating and (iii) fermentation on nutritional and antinutritional components of under-utilized tree legume Parkia roxburghii. The applied methods were found to enhance the protein (15-36 %) and lipid content (11-69 %) and to decrease the other proximal components. All the methods significantly reduced the antinutrients viz. condensed tannins, phytate, saponins, trypsin inhibitors, chymotrypsin inhibitors and lectins. Exceptionally, increased content was documented on total phenolics (117-207 %) and tannins (171-257 %). These reduced antinutritional loads have led to an increase in protein (9-20 %) and starch digestibility (75-254 %). Fermented kernels, the best processed form showed characteristic leguminous pattern for content and composition of amino acids, fatty acids and minerals. So knowledge gathering and exploration of nutritionally balanced under-utilized legumes would enhance food and nutritional security.