Ultrasonic Extraction of Bioactive Compounds From Green Soybean Pods and Application in Green Soybean Milk Antioxidants Fortification

Green soybean (Glycine max L.) pods (GSP) are agro-industrial waste from the production of frozen green soybean and milk. These pods contain natural antioxidants and various bioactive compounds that are still underutilized. Polyphenols and flavonoids in GSP were extracted by ultrasound techniques and used in antioxidant fortification of green soybean milk. The ultrasound extraction that yielded the highest total polyphenol content was 50% amplitude for 10 min, whereas maximum flavonoids content was obtained at 50% amplitude for 15 min. Radical scavenging activity assayed by 2,2-diphenyl-1-picryl-hydrazyl radical (DPPH) and ferric reducing antioxidant power (FRAP) methods did not differ significantly (p>0.05) between the two conditions. Response surface methodology was applied to analyze an optimum ultrasonic-assisted extraction (UAE) condition of these variables. The highest desirability was found to be 50% amplitude with extraction time of 12.5 min. Fortification of the GSP extracts (1-3% v/v) in green soybean milk resulted in higher levels of bioactive compounds and antioxidant activity in a dose-dependent manner. Procyanidins were found to be the main polyphenols in dried GSP which were present at the concentration of 104.1 ± 2.1 mg/g dry sample, respectively. Addition of GSP extracts obtained by using an ultrasound technique to green soybean milk increased its bioactive compound content especially procyanidins as well as its antioxidant activity.

BACTERIOLOGICAL EVALUATION OF LOCALLY PRODUCED SOYBEAN MILK

Soybean milk is a regular beverage commonly sold across the streets and markets in Nigeria and beyond. The demand for soybean milk is fast growing due to its affordability and similarity to dairy milk, including its health benefits. However, there is a growing concern about the public health-related issues associated with this artisanal products production, storage, and distribution. The primary objective of the present investigation was to evaluate the bacteriological composition of the locally produced soybean milk commonly consumed in the Kogi state of Nigeria. The samples for the study were collected from vendors in different locations of the state. The analysis was conducted on the samples using established standard procedures. The result found certain microorganisms such as Micrococcus spp, Lactobacillus spp, Streptococcus spp, Enterobacter spp, Klebsiella spp, and other fungi, which comprises Aspergillus spp and Saccharomyces. The study concludes that the soybean milk consumed in the study parameter was mainly contaminated with varying bacteria.

Study of Formulation of Soybean (Glycine max L.) Milk and Purple Sweet Potato (Ipomoea batatas Poir) Crude Extract in The Making of Non-Dairy Ice Cream

Soybean milk and purple sweet potato are used as the main ingredients in the making of non-dairy ice cream. This study aims to determine the best characteristics of non-dairy ice cream from the formulation of soybean milk and purple sweet potato crude extract. The research design used a completely randomized design with one-factor treatment and four replications and was analyzed statistically with the F test Analysis of Variance at 5% level. The treatment in this study was the formulation of soybean milk and purple sweet potato extract consisting of 60%:0%; 52%:8%; 44%:16%; 36%:24%; 28%:32% of the total ice cream dough. The parameters observed were fat content, protein content, total solids, overrun, melting time, and hedonic sensory evaluation (appearance, texture, taste, and odor). Based on the Indonesian National Standard for ice cream 01-3713-1995 qualified showed that the formulation of soybean milk and purple sweet potato extract crude extract 52%:8% was the best treatment with 9.83% fat content, 2.89% protein content, 34.15% total solids, 49.26% overrun, 13.12 minutes melting time, and hedonic scale for appearance 6.76 (like extremely), texture 5.32 (like), taste 5.58 (like very much), odor 5.56 (like very much). The formulation soybean milk and purple sweet potato crude extract are effects of physicochemical properties and sensory evaluation of non-dairy ice cream.

Utilization of Fluted Pumpkin (Telfairia occidentalis) Seed Milk for the Production of Textured Vegetable Protein

textured vegetable proteins (tofu) using two coagulants namely: lime and calcium sulphide. The textured vegetable proteins were analyzed for their proximate composition and sensory properties. Proximate composition of the texture vegetable proteins revealed a range of 13.67-15.04% moisture, 1.39-3.51% ash, 16.56-21.32% fat, 34.75-48.00% crude protein, 6.64-14.21% crude fibre and 4.34-16.22% carbohydrate. Soymilk curd coagulated with calcium sulphide had higher ash and protein contents while fluted pumpkin seed milk curd coagulated with calcium sulphide had significantly (p<0.05) higher fat and crude fibre contents. There was no significant (p<0.05) difference in the crude protein, moisture, and carbohydrate content of the textured vegetable proteins. Mean sensory scores of the curds showed a range of 4.40-6.70 for colour, 5.05-6.50 for aroma, 3.20-5.20 for taste, 3.95-6.15 for texture, 3.55-6.25 for flavour and 4.18-6.65 for overall acceptability. The sensory result showed that soybean milk coagulated with calcium sulphide was the most preferred sample for all sensory attributes. Fluted pumpkin milk coagulated with calcium sulphide also had sensory attributed comparable with the of soybean milk coagulated with calcium sulphide. Mean sensory scores of fluted pumpkin seed milk and soybean milk curds coagulated with calcium sulphide were more preferred than the samples coagulated with lime juice. The study therefore recommends the use of fluted pumpkin seed milk coagulated with calcium sulphide for the production of tofu with sensory attributes and nutrient content comparable with soybean tofu.