Protein Digestibility and Biochemical Characteristics of Soybean in Three Conditions of Fermentation Processing Step: An in Vitro Study

Protein digestibility of soybean (soaked "S", boiled "B", and fermented "F" soybeans) was changed as 20.58 ± 0.25%, 48.71 ± 0.04%, and 50.21 ± 0.45%, respectively in the preparation of soybean fermentation. After simulated digestion, the increment rate of protein digestibility of both B and F was comparable and higher than that of S accompanying by the accumulations of small protein sub-fractions and essential amino acids. Interestingly, bioactivity parameters of all digested fractions increased by around 2 to 4-fold when digestion stages were progressed with overall F showed the maximum values. Processing not only improves the palatability but also increases protein utilization, the bioavailability of nutrients, and healthy support. The study verified the effect of processing and the benefits of soybean and fermented soybean beyond their basic nutrients which could be claimed as functional foods with higher protein digestibility and indispensable amino acids as well as potential bioactivities.

The Growth of Yeast and Fungi, the Formation of β-Glucan, and the Antibacterial Activities during Soybean Fermentation in Producing Tempeh

Generally, the microorganism involved in soybean fermentation for the production of tempeh is Rhizopus oligosporus. However, Saccharomyces cerevisiae, a type of β-glucan-producing yeast, is known to be present and grow in the fermentation process. This study was aimed at investigating yeast and fungal growth dynamics, β-glucan formation, and antibacterial activity against Escherichia coli during the fermentation after adding S. cerevisiae as an inoculum. The Randomized Complete Block Design (RCBD) was applied with two treatments and three repetitions. Three types of starter culture were S. cerevisiae, R. oligosporus, and the combination of both. The second treatment was fermentation time at room temperature ( 30 ± 2 ° C ) for 0, 8, 16, 24, 32, and 40 hours. The dynamics were observed every eight hours. The obtained data were tested using Tukey’s Honestly Significant Difference (HSD) test. The results indicated that yeast grew during this process from a single S. cerevisiae culture and a mixture of R. oligosporus and S. cerevisiae, but not from R. oligosporus alone. The yeast grew during and until the end of fermentation and decreased after 32 hours in the mixed cultures. The β-glucan formed in tempeh with all types of inoculum, but the antimicrobial activity against E. coli increased with fermentation time and was significantly different between treatments. The highest β-glucan content and antibacterial activity of tempeh are from the mixed culture. In conclusion, the addition of S. cerevisiae and R. oligosporus in soybean fermentation produced tempeh with the highest β-glucan content and antibacterial activity against E. coli. The presence of β-glucans suggests higher health benefits of tempeh.

The Design Of Soybean Fermentation Process Equipment Using Temperature And Humidity Controls For Small Scale Tempe Production.

In making tempeh, the fermentation process is an important process. The fermentation process of tempeh really determines the quality of the tempe produced. In the conventional method, the temperature and humidity in the tempe fermentation process are not regulated, so the fermentation results are strongly influenced by the weather. In general, the fermentation process for tempeh takes about one and a half days. With technological advances in electronics, temperature and humidity can be controlled according to the desired range. By utilizing temperature and humidity controllers in the tempe fermentation process, the time of making tempe can be accelerated without reducing the quality of the tempe produced. From the test results, it was found that the controller was able to maintain an average temperature of 37.63 0C, an average humidity of 57.46%, and was able to accelerate the fermentation process of tempeh within 24 hours with an average power consumption of 212.27 Watt and used to produce tempe for small scale tempe craftsmen.

Fungal-Mediated Biotransformation of Soybean Supplemented with Different Cereal Grains into a Functional Compound with Antioxidant, Anti-Inflammatory and Antitumoral Activities

The aim of this study was to select fungal strains and alternative substrates to increase the production of bioactive compounds by solid-state bioprocessing using soybeans. Initially, from a total of 17 fungi strains, R. oligosporus NRRL 3267, R. oligosporus NRRL 2710, and R. arrhizus NRRL 2582 were pre-selected for presenting the greatest antioxidant activities during soybean fermentation. The three Rhizopus strains were cultured in soybeans supplemented with different cereal grains (brown rice, wheat, corn, and oat) aiming to achieve a higher antioxidant activity. Soybean supplementation with brown rice increased the concentration of phenolic compounds (0.697 to 6.447 mg GAE g-1) significantly compared with the only use of soybean (1.792 to 3.10 mg GAE g-1), using R. oligosporus NRRL 2710. The improved fungal-mediated biotransformation process (R. oligosporus NRRL 2710 with soybeans and brown rice) generated an isoflavone aglycone-rich product, containing different antioxidant compounds, such as trans-cinnamic acid, gallic acid, myricetin, quercetin, and kaempferol. The fermented substrate also showed great potential to inhibit hyaluronidase enzyme (anti-inflammatory activity) and against CaCo-2 tumor cells growth (antitumor activity). The resulting compound could serve as a value-added food and/or feed ingredient and a rich source of bioactive compounds.

PENGARUH LAMA FERMENTASI OLEH Bacillus subtilis TERHADAP KARAKTERISTIK SERE KEDELE

This research aims to find out the effect of soybean fermentation time by Bacillus subtilis to produce sere kedele with the best characteristics. This research used completely randomized design (CRD) with one treatment factor of the fermentation time with 5 period of fermentation time (12, 18, 24, 30 and 36h). Each treatment was repeated 3 times, resulted 15 experimental units. The data were then analyzed with Analysis of Variance method and if the treatment had an effect on the variable, followed by the Duncan test. The result show that fermentation times had significant effect to moisture, ash, protein, fat, carbohydrate, crude fiber content, total acid, pH value, the number microbes, hedonic test for taste, scoring test for taste and overall acceptance of sere kedele. Fermented by B. subtilis for 12h resulted in the best characteristic under the following criteria : 58.05% moisture content, 2.39% ash content, 15.79% protein content, 14.39% fat contetnt, 9,38% carbohydrate content, 6.1 pH value, 0.11% total acid, 9.59log cfu/g the number microbes, color, flavour, texture liked, normal taste with sour taste and overall acceptance liked. Keyword : soybean, sere kedele, Bacillus subtilis, fermentation, traditional food .