Improving the quality of the chicken fillet using chitosan, gelatin, and starch coatings incorporated with bitter orange peel extract during refrigeration.

The preserving potential of biopolymer coatings can be improved by adding natural antimicrobial and antioxidant compounds. The objective of this study was to evaluate the effect of natural coatings (gelatin (Gel), chitosan (Ch), and modified starch (MS)) incorporated with bitter orange peel extract (BOE) on the quality of the chicken fillets during cold. BOE had a high amount of phenolic compounds (145.28 mgGAE/g). Coating the fillets with pure BOE exerted a higher inhibitory effect against bacterial growth compared to composite coatings without extract. Lower microbial count (2-3 log CFU/g on days 9 and 12 of storage) was observed in the samples coated with composite biopolymers incorporated with BOE in comparison to the coatings without BOE. Composite coatings of Gel/MS/BOE showed lower FFA in the fillets followed by Gel/Ch/BOE and MS/Ch/BOE. The lowest TVB-N belonged to MS/Ch/BOE followed by Gel/Ch/BOE and Gel/MS/BOE which were 17.05, 17.39, and 19.40 mg/100 g at the end of the storage. Among the samples, pure BOE, Gel/MS/BOE, Gel/Ch/BOE, and MS/Ch/BOE showed the lowest peroxide value and the coatings containing chitosan had a slower rate of hydroperoxide generation. Drip loss showed a descending trend in all coated samples except for an enhancement in control and BOE-coated fillets, 6.42% and 6.39%, respectively, on day 12 of storage. Samples coated with Gel/MS and Gel/MS/BOE had the lowest drip loss during the storage period (5.96% and 5.98%, respectively). It should be noted that coatings containing chitosan had higher antimicrobial and antioxidant effects. The effect of the coatings as antimicrobial barriers and preservative agents were as follows: Gel/Ch/BOE > MS/Ch/BOE > Gel/MS/BOE. It can be concluded that the applied composite coatings in this work have a high potential to maintain and improve the quality of raw chicken fillets during storage in the refrigerator.

Antimicrobial potential of probiotic cell-free and Carum copticum L. seed extracts co-nanoencapsulated in cellulose acetate fibers.

The aim of this work was to co-nanoencapsulate Lactobacillus acidophilus (LCFE) and Bifidobacterium bifidum (BCFE) cell-free extract and zenyan (Carum copticum L.) seed water (ZWE) and ethanolic (ZEE) extract in electrospun cellulose acetate (CA) nanofibers and evaluate antimicrobial potential. The zeta potential, SEM image, antibacterial (MIC and MBC), and antifungal (MIC and MFC) activities were evaluated. TPC (total phenol content) of water and ethanol extract of zenyan seed were 14.05 and 136.44 mg GAE/g, respectively. A zeta potential of -40.25, -45.80, -43.71, 48.55, 35.50, 47.93, 31.50, 44.69, and -29.61 mV was found for nanofibers of pure CA (cellulose acetate), CA/LCFE, CA/BCFE, CA/ZWE, CA/ZEE, CA/LCFE/ZWE, CA/LCFE/ZEE, CA/BCFE/ZWE, and CA/LCFE/ZEE, respectively. CA electrospun nanofiber loaded with different extracts showed nanosized diameter and uniform structure. Nanoencapsulated extracts showed considerably higher antibacterial and antifungal activity compared to free extracts. Antibacterial activity of lactobacilli cell-free extract was higher than bifidobacteria, which indicated the presence of the higher amount of antibacterial compounds in lactobacilli extract. Gram-positive bacteria (S. aureus and L. monocytogenes) had the lowest MIC and MBC of free and nanoencapsulated extracts while Gram-negatives (E. coli, S. dysenteriae, and S. enteritidis) had higher MIC and MBC. CA-coated zenyan extracts (water and ethanolic) inhibited the growth of the assayed fungi at the MIC ranging 0.25 to 0.95%. These concentrations were 1.5-2 times lower than those obtained for pure extracts. For nanoencapsulated cell-free extracts of both probiotics, the MIC values were about five times lower than the free extracts. The highest antimicrobial activity obtained for CA nanofibers contained zenyan ethanolic extract and cell-free extract of lactobacilli or bifidobacteria.

Comparative antioxidant potential of kefir and yogurt of bovine and non-bovine origins.

The aim of this study was to compare the antioxidant potential of the yogurt and kefir produced from ewe, camel, goat, and cow milk. The antioxidant activity of the samples was assessed by measuring total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity, ferric reducing antioxidant power (FRAP) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical reducing capacity during 20-day storage at 4 ºC. Kefir and yogurt prepared from ewe and camel milk had significantly higher antioxidative potential than samples made from goat and cow milk (P < 0.05). Ewe kefir (74.55-80.11 mg GAE 100 mL-1) showed the highest TPC followed by cow kefir (65-73.15 mg GAE 100 mL-1), camel kefir (61.2-69.91 mg GAE 100 mL-1) and goat kefir (58.31-73.5 mg GAE 100 mL-1) (P < 0.05). Camel yogurt possesses the highest TPC (56.5-68.25 mg GAE 100 mL-1) followed by ewe (40.32-46.5 mg GAE 100 mL-1), cow (29.5-35.5 mg GAE 100 mL-1) and goat (20.03-26.85 mg GAE 100 mL-1) yogurt (P < 0.05). According to DPPH, FRAP, and ABTS results, the antioxidant activity of samples was as follows in descending order: ewe kefir, camel kefir, ewe yogurt, camel yogurt, cow kefir, goat kefir, goat yogurt, cow yogurt. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13197-021-05139-9.

The effect of Amygdalus scoparia Spach and Lepidium sativum L. seed gums on the properties of formulated food supplement for soldiers using Response Surface Methodology.

Today, the lack of a proper nutritional formulation of the diet for soldiers is well felt. In this study, a newly formulated food supplement (FFS) was designed to supply all essential nutrients like protein, carbohydrate, oil, fat-soluble vitamins, and minerals, and Lepidium sativum L. seed (shahi) gum and Amygdalus scoparia Spach (zedo) gum were applied to FFS to promote physicochemical and sensory properties of FFS. The samples were developed by preparing emulsion including meat powder (45.0 g/100 g), soybean powder (25.0 g/100 g), and plant oils (15.0 g/100 g). Iron, zinc, and fat-soluble vitamins (A, D, E, and K) were also added to the formulation, and response surface methodology was used to optimize the effects of shahi and zedo gum at 0.5, 1.0, and 2.0 g/100 g in FFS. The results showed that using hydrocolloids in appropriate amounts enhanced the sensory properties of FFS. Hydrocolloids protected the moisture content of FFS samples and also decreased the reduction of vitamins and minerals during 14 days of storage at 4°C. The hydrocolloids improved the color indices and intrinsic viscosity of samples. The results of this study recommend the use of 1.26 g/100 g of shahi gum and 0.95 g/100 g of zedo gum to produce formulated food supplement for soldiers. This formulation supplies calories and provides some of the essential vitamins and food components to the body.

Preparation and evaluation of food-grade nanoemulsion of tarragon (Artemisia dracunculus L.) essential oil: antioxidant and antibacterial properties.

This study aimed at to formulate a food-grade nanoemulsion of tarragon essential oil (NEO) and investigate its antioxidant and antimicrobial properties. Oil in water NEO was formed by blending 10% of tarragon EO (TEO), 85% water, and a mixture of 5% surfactants, then antioxidant and antimicrobial activities were evaluated. The main components of TEO were estragole, beta-cis-ocimene, beta-trans-ocimene, and l-limonene. NEO droplet had a diameter of 50 nm and a zeta potential of - 30 mV. Results of free radical DPPH scavenging activity revealed that hydrogen donating capacity of the nanoemulsion was significantly higher than TEO and at 2.5 µg/mL concentration it showed complete inhibitory activity against DPPH. The ferric reducing potential was almost similar for TEO and NEO. NEO showed higher antibacterial potential against Staphylococcus aureus and Listeria monocytogenes and Shigella dysenteriae. The results of this work indicated that NEO had higher antioxidant and antimicrobial activity compared with free TEO.

Antibacterial Activity of Carum copticum Essential Oil Against Escherichia Coli O157:H7 in Meat: Stx Genes Expression.

This work were aimed to (a) determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Carum copticum essential oil (EO) against Escherichia. coli O157:H7 in vitro Trypticase Soy Broth, (TSB) and in ground beef; (b) evaluation of the effect of sub-inhibitory concentrations (sub-MICs) of EO on the growth of bacterium in TSB over 72 h (at 35 °C) and ground beef over 9 days (at 4 °C); and (c) investigation of gene expression involved in Shiga toxins production using relative quantitative real-time PCR method. The MIC in broth and ground beef medium were determined as 0.05 (v/v) and 1.75 % (v/w), respectively. In comparison with control cultures, the EO concentration of 0.03 % in broth caused reduction of colony counting as 1.93, 1.79, and 2.62 log10 CFU ml(-1) after 24, 48, and 72 h at 35 °C, and similarly EO (0.75 %) in ground beef resulted to reduction of colony counting as 1.03, 0.92, 1.48, and 2.12 log10 CFU g (-1) after 2, 5, 7, and 9 days at 4 °C, respectively. An increase and decrease in gene expression were observed as result of EO addition (0.03 %) to broth and (0.5 %) to ground beef was noticed, respectively.

Comparative efficacy of Zataria multiflora Boiss., Origanum compactum and Eugenia caryophyllus essential oils against E. coli O157:H7, feline calicivirus and endogenous microbiota in commercial baby-leaf salads.

Ready-to-eat salads using baby-leaf and multi-leaf mixes are one of the most promising developments in the fresh-cut food industry. There is great interest in developing novel decontamination treatments, which are both safe for consumers and more efficient against foodborne pathogens. In this study, emulsions of essential oils (EOs) from Origanum compactum (oregano), Eugenia caryophyllus (clove), and Zataria multiflora Boiss (zataria) were applied by spray (0.8 ml) after the sanitizing washing step. The aim was to investigate their ability to control the growth of potentially cross-contaminating pathogens and endogenous microbiota in commercial baby leaves, processed in a fresh-cut produce company. Zataria EO emulsions of 3%, 5% and 10% reduced Escherichia coli O157:H7 by 1.7, 2.2 and 3.5 log cfu/g in baby-leaf salads after 5 days of storage at 7°C. By contrast, reductions in E. coli O157:H7 counts remained the same when clove was applied at concentrations of 5% and 10% (2.5 log cfu/g reduction). Oregano (10%) reduced inoculated E. coli O157:H7 counts in baby-leaf salads by a maximum of 0.5 log cfu/g after 5 days of storage. Zataria showed strong antimicrobial efficacy against E. coli O157:H7 and also against the endogenous microbiota of baby-leaf salads stored for 9 days. Feline calicivirus (FCV), a norovirus surrogate, survived on inoculated baby-leaf salads during refrigerated storage (9 days at 7°C) regardless of treatment. Refrigeration temperatures completely annulled the effectiveness of the EOs against FCV inoculated in baby-leaf salads as occurred in FCV cultures. This study shows that EOs, and zataria in particular, have great potential use as an additional barrier to reduce contamination-related risks in baby-leaf salads. However, further research should be done into foodborne viruses in order to improve food safety.

Effects of Zataria multiflora Boiss. essential oil on growth and gene expression of enterotoxins A, C and E in Staphylococcus aureus ATCC 29213.

Staphylococcal food poisoning results from the consumption of food in which enterotoxigenic staphylococci have grown and produced toxins. The present study was conducted with three principal aims: i) to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Zataria multiflora Boiss. essential oil (EO) against Staphylococcus aureus ATCC 29213, ii) to evaluate the effect of subinhibitory concentrations (subMIC) of EO on the growth of bacteria over 72 h (at 25 and 35 °C), and iii) to investigate the expression of genes involved in the production of staphylococcal enterotoxins SEA, SEC and SEE over 72 h at 35 °C. The MIC and MBC of Z. multiflora Boiss. EO were 0.03 and 0.04%, respectively. Colony counting at 24, 48 and 72 h of 3 day cultures grown in the presence of 75%MIC of the EO showed that the growth rate was reduced 2.16, 2.78 and 2.91 log 10 cfu/ml at 25 °C, and 1.34, 2.35 and 2.57 log 10 cfu/ml at 35 °C, respectively, compared to control cultures. SubMIC levels of EO also significantly decreased the expression of staphylococcal enterotoxin (SE)-related genes and therefore the production of SEs in a dose dependent manner. For example, when cultured with 75% MIC, the transcriptional levels of sea, sec, see and agrA were decreased 11.7, 9.3, 10.45 and 10.3 fold after 18 h and 13.9, 11.21, 12.44 and 12.52 fold after 72 h in comparison to control, respectively.