Impeding &lt;i&gt;Bacillus&lt;/i&gt; spore germination &lt;i&gt;in vitro&lt;/i&gt; and in milk by soy glycinin during long cold storage

Al-Mohammadi²,

Osman

et al. 2019

Molecules

The present work was carried out to determine the characteristics and antibacterial activity of 7S and 11S globulins isolated from cowpea seed (Vigna unguiculata (L.) Walp.). The molecular mass of 7S globulin was demonstrated by SDS-PAGE bands to be of about 132, 129 and 95 kDa corresponding the α/, α and β subunits. The molecular mass of 11S globulin was demonstrated by SDS-PAGE bands to be existed between 28 and 52 kDa corresponding the basic and acidic subunits. The minimum inhibitory concentrations MICs of 7S and 11S globulins isolated from cowpea seed were determined against Gram positive bacteria viz: Listeria monocytogenes LMG 10470, Listeria ivanovii FLB 12, Staphylococcus aureus ATCC 25923 and Streptococcus pyogenes ATCC 19615, and Gram negative bacteria such as Klebsiella pneumonia ATCC 43816, Pseudomonas aeruginosa ATCC 26853, Escherichia coli ATCC 25922 and Salmonella ATCC 14028 using disc diffusion assay; they were showed to be in the range 10 to 200 µg/mL. Transmission electron microscope (TEM) examination of the protein-treated bacteria showed the antibacterial action of 11S globulin against S. typhimurium and P. aeruginosa was manifested by signs of cellular deformation, partial and complete lysis of cell components. Adding 11S globulin at both concentrations 50 and 100 µg/g to minced meat showed considerable decreases in bacterial counts of viable bacteria, psychrotrophs and coliforms compared to controls during 15 days storage at 4 °C, reflecting a promising perspective to use such globulin as a meat bio-preservative.

Section: Introductionmentioning

confidence: 99%

Characterization and Antibacterial Activity of 7S and 11S Globulins Isolated from Cowpea Seed Protein

Al-Mohammadi²,

Osman

et al. 2019

Molecules

“…The native cowpea seed proteins 7S and 11S were reported to strongly inhibit the in vitro growth of Pseudomonas aeruginosa ATCC 26853 and Salmonella typhimurium ATCC 14028 [14]. Additionally, soybean’s glycinin basic subunit was able to inhibit methicillin-vancomycin intermediate Staphylococcus aureus (MRSA-VISA) while soy glycinin was competent to impede Bacillus spore germination [15,16].…”

Section: Introductionmentioning

confidence: 99%

Antimicrobial Activity and Chemical Constitution of the Crude, Phenolic-Rich Extracts of Hibiscus sabdariffa, Brassica oleracea and Beta vulgaris

Al-Mohammadi²,

Sitohy

et al. 2019

Molecules

Crude, phenolic-rich extracts (CPREs) were isolated from different sources, such as Hibiscus sabdariffa (H. sabdariffa), Brassica oleracea var. capitata f. rubra (B. oleracea) and Beta vulgaris (B. vulgaris) and characterized. These CPREs showed potential antibacterial and antifungal activities. H. sabdariffa CPRE (HCPRE) is the most potent, as it inhibited all tested bacteria and fungi. Total anthocyanins content (TAC), total phenolic content (TPC) and total flavonoid content (TFC) were estimated in all three CPREs. H. sabdariffa contained 4.2 mg/100 g TAC, 2000 mg/100 g of TPC and 430 mg/100 g of TFC in a dry weight sample. GC–MS analysis of HCPRE showed 10 different active compounds that have antimicrobial effects against pathogenic bacteria and fungi, especially alcoholic compounds, triazine derivatives and esters. Scanning and transmission electron microscopy images of Staphylococcus aureus DSM 1104 and Klebsiella pneumonia ATCC 43816 treated with HCPRE (50 μg/mL) exhibited signs of asymmetric, wrinkled exterior surfaces, cell deformations and loss of cell shapes; and adherence of lysed cell content led to cell clumping, malformations, blisters, cell depressions and diminished cell numbers. This indicates death of bacterial cells and loss of cell contents. Aspergillus ochraceus EMCC516 (A. ochraceus, when treated with 100 μg/mL of HCPRE showed irregular cell organelles and cell vacuolation.

“…Moreover, the high concentration of CFG (100 µg g −1 ) was too powerful to allow any increase in the bacterial counts recoded at day zero of minced beef storage. These antibacterial actions are similar but higher than similar ones induced by the cationic native proteins, e.g., soy glycinin, which could limit the bacterial counts in either pasteurized or raw milk preserved under cold conditions [19,58]. It is also higher than the cationic esterified legume protein's preservative action on pasteurized or raw milk [53,[59][60][61][62][63].…”

Section: Discussionmentioning

confidence: 99%

“…The growing consciousness of human health and the justified fear of synthetic compounds have created a research need to explore the utility of natural antimicrobials and antioxidants in extending the shelf-life of stored meat products while maintaining their quality and safety [ 5 , 9 ]. Various natural bio-sources, e.g., plant basic proteins [ 10 , 11 ], phycocyanin [ 12 , 13 , 14 ], milk proteins [ 15 , 16 , 17 , 18 ], herbs [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ], chemically modified proteins [ 29 , 30 , 31 , 32 , 33 ], probiotic bacteria as well as their produced bacteriocins [ 34 , 35 ] may provide potential natural preservatives.…”

Section: Introductionmentioning

confidence: 99%

Catfish Glycoprotein, a Highly Powerful Safe Preservative of Minced Beef Stored at 4 °C for 15 Days

Osman

Al-Mohammadi³

et al. 2020

Foods

Minced beef is a very perishable food product, due to its vulnerability to microbial contamination and its fast quality deterioration. In the current study, the biological efficiency of different concentrations (0, 50 and 100 µg g−1) of the antibacterial catfish glycoprotein (CFG) was estimated as a possible improver of the storability and safety of minced beef preserved at 4 °C for 15 days. CFG (50 and 100 µg g−1) could efficiently control the changes in meat pH during 15 days storage at 4 °C to be within the normal, acceptable levels (6.4 and 6.2, respectively), equalizing the level of the control for minced beef after 6 days of storage under similar conditions. Likewise, the level of metmyoglobin in minced beef stored at the same conditions was maintained at 53.67 and 46.67% by CFG supplementation at 50 and 100 µg g−1, respectively, at the 15th day of storage, which is comparable to the 6th day in case of the control samples. However, the antioxidant effect of CFG against lipid peroxidation was less effective. The antibacterial action of CFG was most pronouncedly powerful and efficient. Supplementation of minced beef with CFG at 50 and 100 µg g−1 significantly (p < 0.05) decreased the bacterial counts at all the time inspection points as compared to the control. After 15 days of storage, the total viable bacteria, psychrotrophic bacterial count and coliforms count were reduced to 3.12, 2.65 and 0.0 log CFU g−1, respectively, in response to CFG (50 µg g−1), and 2.41, 2.04 and 0.0 log CFU g−1, respectively, in response to CFG (100 µg g−1); this compared to 5.13, 4.78 and 2.5 in the control samples after only six days cold storage. Using CFG at 50, 100 and 200 µg g−1 in rat diets did not affect their liver or kidney functions, reflecting the non-toxicity of this substance. Substantiating the antioxidant and antimicrobial potential of CFG in minced beef storage may support its use as a naturally powerful and safe food preservative, as well as a shelf-life extender.