Interactions between isoflavones and soybean proteins: Applications in soybean-protein–isolate production

Ready-to-use therapeutic/supplementary foods from local food resources: Technology accessibility, program effectiveness, and sustainability, a review

Ready-to-Use Therapeutic Food (RUTF) or Ready-to-Use Supplementary Food (RUSF) has been widely used in home-based treatment for severely and moderately acute malnourished children. These programs showed positive results in short term nutritional recovery in children, which were reported in some research settings. Nowadays, the RUTF/RUSF formulation has been improved using a variety of RUTF/RUSF from locally available food ingredients. This paper aims to review the essential aspects of the development and provision of RUTF/RUSF made from local food resources and monitor program effectiveness that warrants the program's sustainability. The modified recipes of RUTF/RUSF were developed following the international dietary guidelines for the rehabilitation of severely and moderately acute malnourished children. The local production of RUTF/RUSF provided some benefits that include empowering the local community, consideration of the common eating pattern, promoting the diversification of food consumption, strengthening food security, as well as supporting the sustainability of RUTF/RUSF production. Results of the PRISMA-based systematic literature review revealed various ingredient developments and processing techniques which could improve the product characteristics and sensory evaluation. RUTF/RUSF in local food production provided different food carriers (e.g., biscuits, wafers) and seemed to be more readily accepted by the children. Furthermore, the program sustainability of RUTF/RUSF depends on a continuous ingredients supply and support from the local government. The findings presented the importance of development of such food supplements based on the local food resources and with improved technology for prevention and rehabilitation of malnourished children.

Karakterisasi Aktivitas Fungsional Senyawa Bioaktif dari Whey Hasil Samping Produksi Tahu

Tofu whey is a by-product obtained during tofu production that contains proteins and peptides, soluble carbohydrates, soy isoflavone, and minerals. This research aimed to characterize the functional properties of whey protein from tofu through separation using membranes with different pore sizes. The permeate resulted from Whatman No. 3 filtration was subjected to acidity (pH) and protein content measurement, while its protein profile was characterized by SDS-PAGE. electrophoresis. Additionally, this permeate was further sieved using ultrafiltration membranes with 30, 10, and 5 kDa cut-off. The corresponding filtrates were analyzed for antioxidant activity, isoflavone content, and ACE inhibitor activity. The tofu whey had a pH of 3.14, crude protein of 2 g/100 g sample, and soluble protein content of 1.47mg/mL. The separation of protein bands using SDS-PAGE showed that the dominant protein or peptides in tofu whey had molecular weights below 18 kDa. The use of ultrafiltration membranes could increase the bioactivity of permeates. The filtrate resulting from the smallest membrane cut-off (i.e., 5 kDa) had a higher antioxidant activity, isoflavone content, and ACE inhibitory activity.

Novel Protein Sources for Applications in Meat-Alternative Products—Insight and Challenges

Many people are increasingly interested in a vegetarian or vegan diet. Looking at the research and the available options in the market, there are two generations of products based on typical proteins, such as soy or gluten, and newer generation proteins, such as peas or faba beans, or even proteins based on previously used feed proteins. In the review, we present the characteristics of several proteins that can be consumed as alternatives to first-generation proteins used in vegan foods. In the following part of the work, we describe the research in which novel protein sources were used in terms of the product they are used for. The paper describes protein sources such as cereal proteins, oilseeds proteins coming from the cakes after oil pressing, and novel sources such as algae, insects, and fungus for use in meat analog products. Technological processes that can make non-animal proteins similar to meat are also discussed, as well as the challenges faced by technologists working in the field of vegan products.

Effects of lactic acid bacteria fermented yellow whey on the protein coagulation and isoflavones distribution in soymilk

This study investigated the soymilk coagulation induced by fermented yellow whey (FYW), which is extensively used as a natural tofu coagulant in China. The aggregations involving proteins and isoflavone particles caused by FYW were analyzed using the proteomic technology and high-performance liquid chromatography, respectively. As indicated, the FYW-induced coagulation of soy proteins mainly occurred at pH 5.80-5.90. When the pH of soymilk decreased, the 7S β, 11S A3 and some of 11S A1a subunits and SBP, Bd, lectin and TA aggregated the earliest, and later did the 11S A4, other 11S A1a, 11S A2 and 11S A1b subunits. The 7S α and α' subunits and TB showed an obvious delay in aggregation. Moreover, isoflavones in the form of aglycones were more likely to coprecipitate with proteins, compared with glycosides. These results could provide an important reference and assistance for future research on the development of traditional FYW-tofu.

Interactions between plant proteins/enzymes and other food components, and their effects on food quality

Plant proteins are the main sources of dietary protein for humans, especially for vegetarians. There are a variety of components with different properties coexisting in foodstuffs, so the interactions between these components are inevitable to occur, thereby affecting food quality. Among these interactions, the interplay between plant proteins/enzymes from fruits and vegetables, cereals, and legumes and other molecules plays an important role in food quality, which recently has gained a particular scientific interest. Such interactions not only affect the appearances of fruits and vegetables and the functionality of cereal products but also the nutritive properties of plant foods. Non-covalent forces, such as hydrogen bond, hydrophobic interaction, electrostatic interaction, and van der Waals forces, are mainly responsible for these interactions. Future outlook is highlighted with aim to suggest a research line to be followed in further studies.

Pressurized water extraction of isoflavones by experimental design from soybean flour and Soybean Protein Isolate

A Doehlert experimental design was conducted and surface response methodology was used to determine the effect of temperature, contact time and solid liquid ratio on isoflavone extraction from soybean flour or Soybean Protein Isolate in pressurized water system. The optimal conditions conducted gave an extraction yield of 85% from soybean flour. For Soybean Protein Isolate compared to soybean flour, the isoflavone extraction yield is 61%. This difference could be explained by higher aglycon content, while aglycon appears to be the least extracted isoflavone by pressurized water. The solid liquid ratio in the ASE cell was the overriding factor in obtaining high yields with both soybean products, while temperature has less influence. A high temperature causes conversion of the malonyls-glucosides and glucosides isoflavone derivatives into glucosides or aglycons forms. pressurized water extraction showed a high solubilization of protein material up to 95% of inserted Soybean Protein Isolate.

Aggregation of soy protein-isoflavone complexes and gel formation induced by glucono-δ-lactone in soymilk

This study investigated the glucono-δ-lactone (GDL)-induced aggregation of isoflavones and soy proteins in soymilk. High-performance liquid chromatography (HPLC) analysis indicated that isoflavones mixed with β-conglycinin (7S) and glycinin (11S) proteins formed 7S-isoflavone and 11S-isoflavone complexes in soymilk supernatant fraction (SSF). Most of the soy protein-isoflavone complexes then precipitated into the soymilk pellet fraction (SPF) following the addition of 4 mM GDL, whereupon the pH value of the soymilk dropped from 6.6 to 5.9. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and HPLC analysis suggest that the addition of 4 mM GDL induced the aggregation of most 7S (α’, α and β subunits), 11S acidic and 11S basic proteins as well as isoflavones, including most aglycones, including daidzein, glycitein, genistein and a portion of glucosides, including daidzin, glycitin, genistin, malonyldaidzin and malonylgenistin. These results provide an important reference pertaining to the effects of GDL on the aggregation of soy protein-isoflavone complexes and could benefit future research regarding the production of tofu from soymilk.

Multi-response optimisation of the extraction solvent system for phenolics and antioxidant activities from fermented soy flour using a simplex-centroid design

A simplex-centroid design comprising three solvents (water, ethanol and methanol) was used to optimise the extraction mixture for phenolics and antioxidant activities from defatted soy flour fermented with Monascus purpureus or Aspergillus oryzae. Total phenolics were more efficiently extracted using only water for both samples. The highest antioxidant activities by the DPPH and ABTS methods were obtained using extraction mixtures containing at least 75 wt% water. Specific water:ethanol:methanol ratios promoted the joint optimisation of the total phenolic and isoflavone contents as well as antioxidant activities: 0.5:0.375:0.125 (wt/wt/wt) and 0.5:0.3:0.2 (wt/wt/wt) from defatted soy flour fermented with M. purpureus or A. oryzae, respectively. However, a water:ethanol ratio of 0.5:0.5 (wt/wt) was deemed optimal because it is comprised of green solvents and yielded results that were greater than 90% of the multi-response maximum values. Both the solvents and the sample matrix strongly influenced the extractability of total phenolics and isoflavones.

Coagulation of β-conglycinin, glycinin and isoflavones induced by calcium chloride in soymilk

The coagulation of β-conglycinin (7S), glycinin (11S) and isoflavones induced by calcium chloride was investigated. Approximately 92.6% of the soymilk proteins were coagulated into the soymilk pellet fraction (SPF) after the addition of 5 mM calcium chloride. SDS-PAGE and two-dimensional electrophoresis analysis indicated that most of the 7S (α', α and β), 11S acidic (A1a, A1b, A2, A3 and A4) and 11S basic (B1a) proteins in the SSF were coagulated into the SPF after treatment with 5 mM calcium chloride. Isoflavones, including daidzein and genistein, were also coagulated into the SPF after the addition of 5 mM calcium chloride. The amounts of daidzein and genistein in the SSF decreased to 39.4 ± 1.6 and 11.8 ± 7.0%, respectively. HPLC analysis suggested that daidzein and genistein were bound with 7S and 11S proteins and then were coprecipitated into the SPF by 5 mM calcium chloride.

Isoflavone extraction from okara using water as extractant

We here report on the use of water as a 'green' extraction solvent for the isolation of isoflavones from okara, a by-product of soymilk production. At a low liquid-to-solid ratio of 20 to 1 and 20 °C, 47% of the isoflavones that can be extracted with 70% aqueous ethanol were extracted. The malonyl-glucosides were fully recovered with a ratio of 20 to 1, while β-glucosides were recovered with an increased liquid-to-solid ratio of 40 to 1. The extraction of aglycones was better at higher ratios, but leveled off before reaching a 100% yield. Temperature hardly affected the total amount of isoflavones. At a 20 to 1 ratio, 20 °C, and pH 10, there was no significant difference (p>0.05) between isoflavone extraction in water and in 70% aqueous ethanol. The results suggest that water may be used as a green alternative for separation of isoflavones from okara.