Gum tragacanth, a novel edible coating, maintains biochemical quality, antioxidant capacity, and storage life in bell pepper fruits.

Bell pepper fruits (Capsicum annuum L.) are prone to both physiological and pathological deterioration following harvest, primarily due to their high metabolic activity and water content. The storage of bell peppers presents several challenges, including weight loss, softening, alterations in fruit metabolites and color, increased decay, and a decline in marketability. The application of edible coatings (ECs) is one of the environmentally friendly technologies that improves many post-harvest quantitative and qualitative characteristics of products. This research investigated the impact of different levels of gum tragacanth (GT) coating (0, 0.25, 0.5, 1, and 2%) on the physiological and biochemical traits of stored bell pepper fruits (BPFs) (8 ± 1°C, 90-95% RH) for 28 days. The results showed the positive effect of coating treatments with higher concentrations of GT, up to 1%. Increasing the concentration of GT to 2% decreased the marketability and quality characteristics of fruits compared to 1% GT. After storage, the physiological weight loss of the fruits treated with 1% GT (10.46%) was lower than that of the uncoated fruits (18.92%). Furthermore, the coated fruits (1% GT) had more firmness, total phenol content, ascorbic acid, and titratable acidity content than uncoated fruits during storage. At the end of storage, the coated BPFs with 1% GT showed higher SOD (97.02 U g-1), CAT (24.38 U g-1) and POD (0.11 U g-1) activities and antioxidant capacity (81.74%) as compared to other treatments. Total soluble solids, total carbohydrates, total carotenoids, pH, malondialdehyde, and electrolyte leakage content increased in coated fruit during storage but were significantly lower than in uncoated fruits. Moreover, the samples coated with GT (1%) maintained good marketability (about 75%), while the marketability of the control (about 40%) was unacceptable. The study shows that GT (1%) coating can be a promising novel treatment option for increasing the storage quality of BPFs.

Effect of Malva neglecta and lactulose on survival of Lactobacillus fermentum and textural properties of synbiotic stirred yogurt.

Yogurt is a popular dairy product and its consumption has been progressively growing over the past few decades by raising consumers' health-consciousness. As yogurt is growing in popularity, manufacturers are continuously seeking for bioactive components such as probiotics and prebiotics, to produce functional yogurt with more beneficial health effects. Therefore, this study aimed to evaluate the effect of Malva neglecta (MN, 0, 5, 10 and 15%) and lactulose (0, 1 and 2%) as prebiotic substances on survival of Lactobacillus fermentum in a half-fat synbiotic stirred yogurt. The results revealed that with increasing MN and lactulose concentrations, the count of Lb. fermentum significantly increased (p < 0.05). At the end of 21-day cold storage, the count of probiotics in yogurt sample having 2% lactulose and 10-15% MN significantly was higher than control (8.37-8.4 vs. 7.73 Log cfu/g). With increasing the amount of MN and lactulose, firmness and chewiness of yogurt samples decreased while adhesiveness increased (p < 0.05). Scanning electron microscopy assessment shown that addition of MN and lactulose resulted in a higher moisture retention in the void spaces. The results revealed that by incorporating lactulose and MN in yogurt formulation, an appropriate synbiotic yogurt could be produced as a novel functional product.

Utilization of Plantago major seed mucilage containing Citrus limon essential oil as an edible coating to improve shelf-life of buffalo meat under refrigeration conditions.

This study is aimed to develop a novel edible coating based on Plantago major seed mucilage (PMSM) and Citrus limon essential oil (CLEO) to increase the shelf-life of buffalo meat during cold storage. The CLEO was firstly isolated by the hydrodistillation method, and it contained mainly limonene (40.5%) and carene (15.4%) with remarkable antioxidant activity (55.7%, 63.8%, and 51.85% based on the DPPH-radical scavenging, ABTS-radical scavenging, and carotene-linoleic acid bleaching tests, respectively) and antibacterial effect against some pathogenic and spoilage microorganisms. The CLEO (0%, 0.5%, 1%, 1.5%, and 2%) was then incorporated into PMSM solution to develop a novel CLEO-loaded PMSM edible coating for improving the shelf-life of buffalo meat. The edible coating was able to significantly reduce the progression of lipid oxidation (peroxide value) and microbial growth (total viable count, psychrotrophic bacteria, Escherichia coli, Staphylococcus aureus, and fungi) in buffalo meat during storage period of 10 days at 4°C in comparison with the control (noncoated sample). The meat hardness and sensory properties (i.e., odor, color, appearance, texture, and overall acceptability) were also maintained better upon edible coating applications. Based on the results, the CLEO-rich PMSM edible coating could be applied as a new and effective preservative to improve the stability of meat products to lipid oxidation and microbial spoilage.

The impact of Qodume Shirazi seed mucilage-based edible coating containing lavender essential oil on the quality enhancement and shelf life improvement of fresh ostrich meat: An experimental and modeling study.

Today, food consumers prefer to use the foods that contain natural preservatives. The purpose of this study was to investigate the effect of Qodume Shirazi seed mucilage (QSSM) and lavender essential oil (LO) on the preservation of ostrich meat during cold storage. The chemical compounds of LO were identified through gas chromatography-mass spectrometry (GC/MS). The ostrich meat samples were coated with the mucilage containing the essential oil at concentrations of 0%, 0.5%, 1%, 1.5%, and 2%, v/v. The control and the coated ostrich meat samples were kept at 4°C and analyzed for microbiological (total viable count, psychrotrophic count, Escherichia coli, Staphylococcus aureus, coliforms, and fungi), physicochemical (moisture content, pH, texture, and color parameters), and sensorial (odor, color, and total acceptance) characteristics during 9 days of storage. GC/MS identified 12 compounds in the essential oil, among which linalool was the major one (43.3%). The lightness (L* value) and hardness of all the ostrich meat samples were reduced during the storage. From a microbiological point of view, the cold storage duration for the control and the coated sample without the essential oil was only 3 days, while for coated samples containing 0.5%, 1%, 1.5%, and 2% essential oil, it was 3, 3, 6, and 9 days, respectively. The coated ostrich meat containing 2% LO had an appropriate quality with an expanded shelf life. The results showed that neural network with 10 neurons in the hidden layer had the lowest mean squared error and mean absolute error and the highest correlation coefficient for predicting the quality and microbial properties of the coated meat samples during storage.

Gamma-aminobutyric acid production by Lactobacillus brevis A3: Optimization of production, antioxidant potential, cell toxicity, and antimicrobial activity.

In this study, whey powder was used as the basic compound for fermentation culture and the production of bioactive gamma-aminobutyric acid (GABA) compound. GABA is a nonprotein four-carbon amino acid that inhibits stress signals by preventing brain signals, reducing stress, and being effective in treating neurological disorders and decreasing the growth of cancer cells. Due to the side effects caused by the chemical type of GABA, the biological production of GABA has attracted. Three levels of whey powder (5%, 10%, and 15%), and monosodium glutamate (MSG) (1%, 3%, and 5%) were selected at temperatures (25, 30, and 37°C) and after fermentation, the presence of GABA in the culture medium was examined by thin-layer chromatography. The optimal amount of GABA was measured by using high-performance liquid chromatography. The results of the central composite design of the response surface methodology at a significant level of 95% showed that the optimal treatment was 14.96% whey powder, 4.95% MSG at temperature of 37°C and fermentation for 48 hr and under these conditions, GABA production was 553.5 ppm. The results of the fermented extract tests showed that the highest antimicrobial activity was on Escherichia coli and the highest free radical scavenging was 59.67%. The IC50 level in the Caco-2 cancer cell cytotoxicity test was 39.5 mg/ml. According to the results, the combination of whey with MSG can be used as a cheap substrate to produce a valuable bioactive GABA product, and the cellular extract of this fermentation can also be used as an antimicrobial and antioxidant compound in food and pharmaceutical formulations.

Biological reduction of aflatoxin B1 in yogurt by probiotic strains of Lactobacillus acidophilus and Lactobacillus rhamnosus.

The present study was conducted to investigate the ability of two probiotic strains, L. acidophilus PTCC 1643 and L. rhamnosus PTCC 1637, to bind aflatoxin B1 (AFB1, 20 ng/ml) in comparison with yogurt starter cultures, at equal bacterial count (~ 109 LogCFU/ml) during a 21-day storage period at 4 °C. All assessed treatments exhibited high percentages of AFB1-binding, ranged from 64.56 to 96.58%. However, the ability of probiotic bacteria was statistically higher than yogurt starter cultures. Aflatoxin binding ability of the selected lactic acid bacteria was dependent on both time and bacteria species. The highest and the lowest percentages of AFB1-removal was observed at 11th day of cold storage by L. rhamnosus (96.58 ± 3.97%) and at the first day of storage for yogurt starter cultures (64.56 ± 5.32%), respectively. The stability of bacterial cells-AFB1 complex was remarkable, since only 0.84-26.75% of bounded AFB1 was released from bacterial cells after 3 times washing during the storage period.

Optimization of gluten-free cake formulation enriched with pomegranate seed powder and transglutaminase enzyme.

Celiac disease is an autoimmune disorder caused by a permanent intolerance of genetically susceptible persons to gluten proteins and intake of gluten-free diets throughout their life is the only treatment way. Therefore, studies dealing with the production and improvement of gluten-free food products, especially bakery products are of great importance. The aim of this study was to investigate the effect of adding pomegranate seed powder (0-50%) and transglutaminase enzyme (0-1.2%) on physicochemical, sensory and textural properties of gluten-free cake made from rice flour. The results showed that pomegranate seed powder and transglutaminase had positive effects on fiber and ash contents, and porosity; whilst, the incorporation reduced the weight loss, volume and specific volume. Optimization process was performed and optimum gluten-free formulation contained 25.75% pomegranate seed powder and 0.97% transglutaminase. The optimized gluten-free cake showed higher total antioxidant activity, ash, fiber, protein and moisture contents and lower peroxide value, volume index and porosity compared to the control one. The porosity decrement was confirmed in the optimized cake by scanning electron microscopy images.

Modeling of ultrasound-assisted extraction, characterization and in vitro pharmacological potential of polysaccharides from Vaccinium arctostaphylos L.

In the study, Box-Behnken design was used to optimized the operational parameters involved in ultrasound-assisted extraction (UAE) of Vaccinium arctostaphylos polysaccharide (VAP) including ultrasound power, extraction temperature and time and water to raw material ratio. The highest extraction polysaccharide was obtained at 100W, 19.12min, 79.32C and 20 (ml water/g powdered Vaccinium arctostaphylos). Under these condition, total anthocyanin, total phenolic contents and total flavonoid were 10.16mlg/g, 0.43mlg/g and 0.58mlg/g, respectably. Also, structure of polysaccharide was identified by GC-Mass Fourie transform-infrared spectroscopy (FT-IR). Then, we demonstrated that VAPs had significantly scavenging activities against 2,2-diphenyl-1-picrylhydrazyl and hydroxyl radicals in vitro. The effect of degradation of DPPH was increased by increasing the concentration of polysaccharide up to 15mg/ml. The anti-microbial activity of the resulted polysaccharide with highest concentration (15mg/ml) was the following in order of inhibition zone diameter: B. panis (9.89mm)>S. aureus (9.12mm)>Sh. dysenteriae (7.45mm)>E. coli (6.38mm). VAPs can thus be used as anexcellent antioxidant and antimicrobial ingredient in food and medicinal preparations.

Characterization of Hypericum perforatum polysaccharides with antioxidant and antimicrobial activities: Optimization based statistical modeling.

In this study, the extracting parameters of crude polysaccharides (CPSs) from the Hypericum perforatum (HP) including extraction time (ETi, 60-180min), extraction temperature (ETe, 60-90°C), and the water/solid ratio (W/S, 10-30 was optimized by using three-variable-three-level Box-Behnken design-response surface methodology (BBD-RSM) based on the single-factor experiments. The optimal extraction conditions were as follow: ETi 117.5min, ETe 74.28°C, and W/S 20.3:1. Under these conditions, the experimental yield was 6.69%. Fourier transform-infrared spectroscopy (FT-IR) was used to identify structure of polysaccharide extracted at the optimal operating point. HP-CPSs was proved to possess antioxidant activities including 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and OH free-radicals scavenging activates in vitro. The antibacterial activities of HP-CPSs against Escherichia coli, Shigella dysenteriae and Salmonella typhi, Bacillus cereus and Staphylococcus aureus were evaluated by determining clear growth inhibition zone diameters and by essays in liquid media. Overall, the results indicated that those polysaccharides could offer promising sources of polysaccharides for future application as antioxidant ingredients in the food industry.

Effect of Persian and almond gums as fat replacers on the physicochemical, rheological, and microstructural attributes of low-fat Iranian White cheese.

The effect of Persian and almond gums (0, 0.1 and 0.2% (w/w)) as fat replacers and milk fat (0.4, 0.9, and 1.4% (w/w)) on physicochemical and rheological characteristics and microstructure of low-fat Iranian White cheese was studied. Persian and almond gums both effectively increased moisture-to-protein (M:P) ratio of low-fat cheese samples which in turn led to a significant reduction in the hardness parameters fracture stress and Young's and storage (G') moduli (p < .05); however, the effect of Persian gum was more pronounced (p < .01). Gum addition promoted cheese yield and proteolysis rate (p < .05). Response surface optimization described that supplementation of cheese milk containing 0.9% fat with 0.2% Persian gum and 0.12% almond gum would result in a low-fat cheese with textural properties similar to its full-fat counterpart. Scanning electron microscopy revealed that the fat replacers produced full-fat-like structure in the low-fat Iranian White cheese, when incorporated at the optimum levels.

Short communication: Effect of whey protein addition and transglutaminase treatment on the physical and sensory properties of reduced-fat ice cream.

The effects of whey protein addition and transglutaminase treatment, alone and in combination, on the physical and sensory properties of reduced-fat ice cream were investigated. Adding whey protein with or without enzyme treatment decreased melting rate, overrun, and hardness of the reduced-fat ice cream; however, the enzyme-treated sample had a higher melting rate and overrun and softer texture. Whey protein-fortified samples showed higher melting resistance, but lower overrun and firmer texture compared with the enzyme-treated sample without added whey protein. Whey protein addition with or without transglutaminase treatment caused an increase in apparent viscosity and a decrease in flow index of the reduced-fat ice cream; nevertheless, the flow behavior of full-fat sample was most similar to the enzyme-treated reduced-fat sample with no added whey protein. Descriptive sensory analyses showed that neither whey protein addition nor transglutaminase treatment significantly influenced the flavor and odor of reduced-fat ice cream, but they both noticeably improved the color and texture of the final product. The results of this study suggest that whey protein addition with transglutaminase treatment improves the physical and sensory properties of reduced-fat ice cream more favorably than does whey protein addition or transglutaminase treatment alone.

Polysaccharide of caper (Capparis spinosa L.) Leaf: Extraction optimization, antioxidant potential and antimicrobial activity.

Three-variable-three-level Box-Behnken design-response surface methodology (BBD-RSM) based on the single-factor experiments was used to optimize the extracting parameters of crude polysaccharides (CPSs) from the Capparis spinosa leaves (CSL) including extraction time (ETi, 60-120min), extraction temperature (ETe, 60-80°C), and the water/solid ratio (W/S, 6-16). The optimal process conditions in order to the highest yield (6.73%) of CSL-CPSs were 119.8min ETi, 72.84°C ETe, and 15.97:1W/S.Structure of polysaccharide extracted at the optimal operating point were identified by Fourier transform-infrared spectroscopy (FT-IR). CSL-CPSs (50-300µg/L) revealed significantly scavenging activities against 2,2-diphenyl-1-picrylhydrazyl (DPPH)and OH free-radicals in vitro. A much more antimicrobial activity using this polysaccharide against Gram-negative bacteria (Escherichia coli, Shigella dysenteriaeandSalmonella typhi) was found than Gram-positive bacteria (Bacillus panis and Staphylococcus aureus). CSL-CPSs can thus be used as anexcellent antioxidant and antimicrobial ingredient in food and medicinal preparations.