Effects of Radishes, Apples, and Pears on the Lactic Acid Bacteria and Nutritional and Functional Qualities of Flavored Soy Sauce

Changes in quality components and antioxidant activity of peony seed soy sauce during low-salt solid-state fermentation

BACKGROUND

In this study, the fermentation conditions of peony seed soy sauce (PSSS) koji were optimized by response surface method, and the quality components and antioxidant activity of PSSS were investigated at different low-salt solid-state fermentation stages.

RESULTS

Results of response surface method showed that the optimal fermentation conditions were 460.6 g kg^-1 water content, 48.6 h culture time, 31.5 °C culture temperature and ratio 2.1:1 (w/w) of peony seed meal:wheat bran, with the highest neutral protease activity (2193.78 U g^-1 ) of PSSS koji. PSSS had the highest amino acid nitrogen (7.69 g L^-1 ), salt-free soluble solids (185.26 g L^-1 ), total free amino acids (49.03 g L^-1 ), essential free amino acids (19.58 g L^-1 ) and umami free amino acids (16.64 g L^-1 ) at 20 days of fermentation. The highest total phenolics were 5.414 g gallic acid equivalent L^-1 and total flavonoids 0.617 g rutin equivalent L^-1 , as well as the highest DPPH radical scavenging activity (86.19%) and reducing power (0.8802, A₇₀₀ ) of PSSS fermented at 30 days. Sensory evaluation showed that fermentation of 20 days and 25 days could produce a better taste and aroma of PSSS than 15 days and 30 days.

CONCLUSION

PSSS had the highest quality components in the middle of fermentation (20 days) and the highest antioxidant activity in the late fermentation period (30 days). These results demonstrated that peony seed meal could be used to produce high-quality soy sauce with high antioxidant activity. © 2023 Society of Chemical Industry.

Effects of Novel Preparation Technology on Flavor of Vegetable-Soy Sauce Compound Condiment

Vegetables contain important bioactive substances which have unique tastes and aromas and provide beneficial effects to human health. In this study, multiflavor blended soy sauce was prepared with the juice of eight kinds of vegetables, dried shrimp boiled stock, and six kinds of commercial soy sauce as raw materials, and thermal ultrasound was used as the sterilization method. The effects of adding different formulas of vegetable and seafood stock on the basic physical and chemical parameters, nutrition, antioxidant activity, flavor, and taste of soy sauce were investigated. The results showed that the basic physicochemical indices such as pH, total acid, color, soluble solids, and amino acid nitrogen of the product with a ratio of soy sauce to vegetable-seafood stock of 1:0.5 (v/v) could meet the production standards of soy sauce, and its flavor, taste, and sensory scores were relatively good, with the highest likeability (overall acceptability). The mixed soy sauce with a ratio of 1:2 (v/v) had higher vegetable and seafood flavors, and different vegetable flavors (celery, carrot, and onion) were more obvious, but its nutritional index was relatively low. Multiflavor vegetable-soy sauce can be used for quick cooking by chefs of catering enterprises, and may be used as a seasoning bag for prefabricated dishes and convenient foods, attracting increasing attention from manufacturers and consumers.

Degradation mechanism of aflatoxin B1 and aflatoxin G1 by salt tolerant Bacillus albus YUN5 isolated from 'doenjang', a traditional Korean food

Aflatoxins are the mycotoxins that contaminate food and feed and pose health hazards to humans and animals. Here, Bacillus albusYUN5 was isolated from doenjang (Korean fermented soybean paste) and examined for aflatoxin B1 (AFB1) and aflatoxin G1 (AFG1) degradation capabilities. The highest degradation of AFB1 (76.28 ± 0.15%) and AFG1 (98.98 ± 0.00%) was observed in the cell-free supernatant (CFS) ofB. albusYUN5, whereas negligible degradation was observed in intracellular fraction, viable cells, and cell debris. Furthermore, heat (100 °C) and proteinase K treated CFS possessed AFB1 and AFG1 degradation ability, suggesting that substances other than proteins or enzymes are responsible for the degradation. Optimal degradation of AFB1 and AFG1 by the CFS was achieved at 55 °C and 45 °C, respectively, and at pH 7-10 and salt concentration of 0-20%. Liquid chromatography-mass spectroscopy analysis of the degraded products revealed that either the difuran or lactone ring of AFB1 and lactone ring of AFG1 is the main target site by CFS of B. albus YUN5. A slightly better reduction of AFB1 and AFG1 was observed in doenjang treated with CFS and viable cells of B. albus YUN5 compared to those without CFS and B. albus YUN5 treated doenjang during one year of fermentation, suggesting the applicability of B. albus in real food.

Arbuscular mycorrhizal fungi species improve the fatty acids profile and nutrients status of soybean cultivars grown under drought stress

AIMS

To investigate the effects of arbuscular mycorrhizal fungi (AMF) species on the absorption and distribution of mineral nutrients in soybean cultivars under drought stress, an experiment was carried out through a factorial method in the form of randomized complete blocks with six replicates in 2020.

METHODS AND RESULTS

Experimental factors include: drought stress at three irrigation levels (well-watered [WW], medium stress [MS] and severe stress [SS], i.e., 100%, 70% and 40% FC), soybean cultivars at two levels (Sepideh and Williams), and mycorrhizae application at four levels (nonapplication, Funneliformis mosseae, Glomus hoi, Rhizophagus intraradices). The results indicated that drought stress increased the concentration of grain potassium (K) and sodium (Na), leaf K, stem and leaf Na, and decreased the concentrations of grain phosphorus (P), copper (Cu), and zinc (Zn), leaf P, stem and leaf Cu, and manganese (Mn). In addition, there was no significant difference in terms of concentrations of grain K. The highest reduction was observed under SS conditions (40% FC). G. hoi colonization increased the concentrations of grain P and Zn, leaf K and Cu and stem Mn under SS conditions (40% FC). In addition, compared to Sepideh cv., Williams cv. showed higher stress resistance. Seed oil content decreased in the plants exposed to drought stress. Severe drought treatments have a deleterious effect on seed fatty acid composition, resulting in enhanced linoleic, oleic and linolenic acids.

CONCLUSION

AMF colonization is a useful tool for improving the plant nutrient uptake, fatty acid profile, efficiency of resource utilization and stabilizing yield, hence reducing the production risks of crops grown under drought stress conditions. It was concluded that AMF colonization should be employed to help alleviate the adverse effects of drought stress.

SIGNIFICANCE OF STUDY

AMF colonization is an effective biotechnological strategy that can alter nutrient uptake and fatty acid composition and enhance oil quality in soybean cultivars under drought conditions.