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In this study, ultrasonication (US) (50 W, 30 kHz, 1–6 min) was used to increase the efficiency of Limosilactobacillus reuteri PTCC 1655 fermentation process (37 °C; 30 h) of Bakraei juice. Total sugars, pH, Brix, organic acids, vitamin C, polyphenols, antioxidant activity, α-amylase inhibition and anti-inflammatory properties were measured during the fermentation period. The results showed that by increasing the ultrasound time up to 5 min, pH, vitamin C, citric acid, and polyphenolic compounds decreased, while lactic acid, antioxidant capacity, α-amylase inhibition and anti-inflammatory properties were increased. When the ultrasound time was increased up to 6 min, compared to the non-ultrasound-treated sample, the efficiency of the fermentation process decreased and promoted a decrease in the microbial population, lactic acid levels, antioxidant activity, α-amylase inhibition, and anti-inflammatory properties of the juices. The initial anti-inflammatory activity (11.3%) of juice reached values of 33.4% and 19.5%, after US treatments of 5 and 6 min, respectively, compared to the non-sonicated juice (21.7%), after 30 h of fermentation. As a result, the use of ultrasound in the controlled fermentation process can increase the efficiency of fermentation process. [ABSTRACT FROM AUTHOR]

Summary: In the present study, the effects of continuous and pulsed ultrasound (100 W, 30 kHz, 25–75% amplitudes for 30 min) and fermentation process (37°C for 24 h) by Lactobacillus helveticus PTCC 1332 on biological activities of Chortan were investigated. The obtained results showed that fermentation enhanced protease content (36.27% (neutral), 37.57% (acid), 39.28% (alkaline) protease), peptide concentration (45.27%) and antioxidant activity (33.69% (DPPH), 132.85% (ABTS)) of samples compared to unfermented ones. Additionally, an increase in ultrasound amplitude (except for continuous at 75%) promoted the protease enzymes, peptides and radical scavenging activity of the fermented and unfermented samples. Our results indicated that the ultrasound and fermentation treatments complemented each other. Depending on the experimental conditions, the effect of continuous ultrasound on samples was sometimes lower, sometimes similar and sometimes higher than that of pulsed treatment. Therefore, selection of an appropriate ultrasound mode and amplitude can improve the biological activity of Chortan. [ABSTRACT FROM AUTHOR]

In order to reduce the risk of microbial contamination in fresh radish (Raphanus raphanistrum) and ensure its safety, combined effects of ultrasound and lactic acid in inactivating microorganisms and quality changes of radish were studied. Fresh radish samples were inoculated with Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Shigella sonnei separately and were treated with lactic acid (L) 1% and 2%, ultrasound (U) with the amplitude of 0%, 25%, 50%, and 75% for 15 and 30 min and their combination. The quality parameters, including total phenol content, firmness, and total color change, were evaluated on the day of the experiment and after 24 hr of cold storage. Results showed that both applied treatments and their combinations had significant (p <.05) inhibitory effect on all of the studied bacteria. Total phenolic content of the ultrasound treated samples led to higher amounts comparing to other samples. Results showed that using ultrasound power (75%), for 30 min significantly (p <.05) decreased the firmness of samples after 24 hr of cold storage. In conclusion, the application of ultrasound and lactic acid can extend the shelf life of fresh radish. [ABSTRACT FROM AUTHOR]

Summary: Aflatoxin M1 (AFM1) and ochratoxin A (OTA) are two main mycotoxins in milk and dairy products. In the present work, the ability of four Lactobacillus strains (L. plantarum PTCC 1058, L. plantarum LP3, L. plantarum AF1 and L. plantarum LU5) to remove AFM1 and OTA in fermented cream was studied during 24 h fermentation. The antifungal activity of the mentioned lactobacilli against the defined fungi (Aspergillus flavus PTCC 5004, Aspergillus parasiticus PTCC 5018, Aspergillus nidulans PTCC 5014, Aspergillus ochraceus PTCC 5060) was also evaluated. The results showed that the cell counts of all strains were increased by 64–70% during fermentation. All Lactobacillus strains decreased the amount of AFM1 significantly (P ≤ 0.05) in the range of 26–52%, which the highest AFM1‐reducing effect was related to L. plantarum LU5 (from 0.5 to 0.24 μg kg−1). The mean OTA removal by Lactobacillus strains in fermented cream also ranged from 32 to 58%. Amongst Lactobacillus strains, the cell‐free culture supernatants of L. plantarum LU5 showed the highest (inhibition zone of 26.7 ± 1.2 mm) and L. plantarum LP3 and L. plantarum PTCC 1058 the lowest antifungal activities. The fermented creams contained Lactobacillus strains exhibited the highest and lowest antifungal activities against A. ochraceus and A. parasiticus, respectively. L. plantarum LU5, with the inhibition zone of 27.6 ± 0.9 mm, was the most effective fungal inhibitor, while L. plantarum PTCC 1058 had the lowest antifungal activity. Effect of fermentation on mycotoxins. [ABSTRACT FROM AUTHOR]

The effect of ethanolic Thymus daenensis extract (TE) incorporation, as a natural antioxidant, on oxidation stability as well as the formation of trans fatty acids in used frying oil in preparation of panjereie bread (Iranian traditional cookie) was investigated. The frying was done with a mixture of soybean and palm (1:1) edible oils contained (1, 2 and 3) % TE, in comparison to TBHQ (1 %), at180 °C for 1 hour. According to related results of acid value, peroxide value, conjugated diene value, anisidine value, and total polar compounds analysis; employing the TE or synthetic antioxidant could reduce the formation of oxidation compounds in frying oil in addition to fried panjereie bread. However, by elapsing of time, radical scavenging activity decreased for all samples, the lowest scavenging activity can be correlated to the samples containing 3 % TE. The slowest kinematic viscosity was observed in samples containing 3 % TE. However, the formation of trans fatty acids was increased by elapsing the frying time, the lowest amount of trans fatty acids was observed in prepared panjereie bread with oil containing 3 % TE. Moreover, TE of (1 and 2) % and TBHQ did not have significant difference (P<0.05). The TE can be used as a natural antioxidant to reduce the oxidation as well as formation of trans fatty acids in frying oils and fried products. [ABSTRACT FROM AUTHOR]

Date syrup is rich in fermentable sugars and may be used as a substrate for different microbial fermentations, including lactic acid fermentation processes. The beneficial effects of ultrasounds (US) on bioprocesses have been reported for several microorganisms, due to the enhancement of cell growth, as well as improvements in yields and productivities. Therefore, US treatments (30 kHz, 100 W, 10–30 min) were applied to two lactobacilli (Lactobacillus helveticus PTCC 1332 and Lactobacillus acidophilus PTCC 1643), during fermentation using date syrup as substrate. The effects on lactic acid fermentation were evaluated by analyzing cell growth (dry cell weight and viable cell count), substrate consumption (quantification of glucose and fructose), and product formation (quantification of lactic acid) over time. The effects of US were also evaluated on cell membrane permeability. Both lactobacilli were able to grow well on date syrup without the need for addition of further ingredients. The US effects were highly dependent on treatment duration: treatments of 10- and 20-min stimulated lactobacilli growth, while the treatment extension to 30 min negatively affected cell growth. Similarly, the 10- and 20-min treatments increased sugar consumption and lactic acid production, contrarily to the 30-min treatment. All US treatments increased cell membrane permeability, with a more pronounced effect at more extended treatments. The results of this work showed that application of appropriate US treatments could be a useful tool for stimulation of lactic acid production from date syrup, as well as for other fermentative processes that use date syrup as substrate. [ABSTRACT FROM AUTHOR]

The effect of ethanolic Thymus daenensis extract (TE) incorporation, as a natural antioxidant, on oxidation stability as well as the formation of trans fatty acids in used frying oil in preparation of panjereie bread (Iranian traditional cookie) was investigated. The frying was done with a mixture of soybean and palm (1:1) edible oils contained (1, 2 and 3) % TE, in comparison to TBHQ (1 %), at180 °C for 1 hour. According to related results of acid value, peroxide value, conjugated diene value, anisidine value, and total polar compounds analysis; employing the TE or synthetic antioxidant could reduce the formation of oxidation compounds in frying oil in addition to fried panjereie bread. However, by elapsing of time, radical scavenging activity decreased for all samples, the lowest scavenging activity can be correlated to the samples containing 3 % TE. The slowest kinematic viscosity was observed in samples containing 3 % TE. However, the formation of trans fatty acids was increased by elapsing the frying time, the lowest amount of trans fatty acids was observed in prepared panjereie bread with oil containing 3 % TE. Moreover, TE of (1 and 2) % and TBHQ did not have significant difference (P<0.05). The TE can be used as a natural antioxidant to reduce the oxidation as well as formation of trans fatty acids in frying oils and fried products. [ABSTRACT FROM AUTHOR]

Background: The lipase enzyme (EC: 3.1.1.3) is one of the most important catalysts in food, dairy, detergent, and textile industries., Objective: This study was performed to identify, isolate and characterize of lipase producing bacterial strain from agrifood wastes and to identify and characterize of their lipase genes., Materials and Methods: In the present study, two lipase-producing isolates were identified from the effluent of Golbahar meat products and Soveyda vegetable oil factories using in silico and in vitro approaches., Results: The results of morphological, biochemical, and molecular characterizations showed that both lipase-producing isolates belong to the Bacillus amyloliquefaciens species. Phylogenetic analysis confirmed the results of phenotypic, biochemical, and molecular characterizations. The results showed differences between LipA and LipB in the Golbahar and Soveyda isolates. Three different amino acids (residues 14, 100, and 165) were observed in LipA and one different amino acid (residue 102) was detected in LipB extracellular lipases. The protein molecular weight of the two extracted lipases ranged from 20 to 25 kDa. The identified extracellular lipases also had different physicochemical features. The maximum lipase activity of the Golbahar and Soveyda isolates was observed at 45 °C and at the pH of 8, but the Golbahar isolates exhibited higher lipase activity compared to the Soveyda isolates. The Golbahar and Soveyda isolates exhibited different activities in the presence of some ions, inhibitors, denaturing agents, and organic solvents and the Golbahar isolates showed better lipase activity than the Soveyda isolates., Conclusions: In this study, two extracellular lipase-producing isolates of B. amyloliquefaciens were identified from different food industries, and their characteristics were investigated. The results of various investigations showed that the lipases produced by the Golbahar isolate have better characteristics than the lipases of the Soveyda isolate. The Golbahar lipases have a suitable temperature and pH activity range and maintain their activity in the presence of some ions, inhibitors, denaturing agents, and organic solvents. After further investigation, the Golbahar isolate lipase can be used in various industries. In addition, this lipase can be used enzyme engineering processes and its activity can be arbitrarily changed by targeted mutations. The results of this study can increase our knowledge of extracellular lipases and may turn out to have industrial applications., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright: © 2021 The Author(s); Published by Iranian Journal of Biotechnology.)