The Effects of Liposomal Encapsulated Thyme Extract on the Quality of Fish Mince andEscherichia coliO157:H7 Inhibition During Refrigerated Storage

Fortifying of probiotic yogurt with free and microencapsulated extract of Tragopogon Collinus and its effect on the viability of Lactobacillus casei and Lactobacillus plantarum

In this study, the effect of free and microencapsulation of Tragopogon Collins extract (TPE) on the properties of probiotic yogurt was investigated. For this purpose, first, TPE was extracted by ultrasound method. The amounts of phenolic and flavonoid compounds in TPE were 890.04 mg/g gallic acid and 512.76 mg/g extract (respectively), and it had high antioxidant and antimicrobial properties. Then, the extract was encapsulated by maltodextrin-whey protein concentrate. The results related to the particle size, zeta-potential, and microencapsulation efficiency of the TPE microencapsulation were 93.87 nm, 18.99 MV, and 64.35% respectively. In order to investigate the effect of nano- and free TPE on the properties of yogurt during a 15-day storage period of 5 treatments including control, nano- and free TPE at 750 and 1,000 ppm were provided and the physicochemical properties, probiotic bacteria viability, and sensory properties were investigated. The results showed that adding TPE to yogurt affects the physicochemical properties, probiotic bacterial viability, and sensory properties were investigated. The results showed that adding TPE to yogurt affects the physicochemical properties. TPE samples had lower pH, less syneresis, and more acidity, viscosity, and antioxidant properties compared to the control sample (p < .05). Furthermore, in these samples, the viability of probiotic bacteria during storage was higher than the control treatment and the sensory properties were acceptable. In most cases, better results were observed in nano-TPE treatment. Therefore, by industrial production of probiotic yogurt containing nano-TPE as a functional food, a new choice will be provided for consumers of dairy products that would have more desirable nutritional value and sensory properties.

Effects of cinnamon essential oil and Persian gum on preservation of pomegranate arils

Given the high perishability of pomegranate arils, edible antimicrobial coating will enhance their shelf life and maintain their marketability. An antimicrobial coating was prepared using 1% (w/v) soluble part of Persian gum (PG) and different concentrations (0.25%, 0.50%, and 0.75% (v/v)) of cinnamon essential oil (CEO) to extend the shelf life of pomegranate arils. Microbiological, chemical, physical, and sensorial characteristics of coated and uncoated samples were evaluated at 7-day intervals. Total anthocyanin (TAN), titrable acidity (TA), and ascorbic acid showed a decreasing trend, during the whole period of the storage. TAN, TA, and ascorbic acid decreased from 119.8 to 44.5 mg/L, 1.6% to 1.37%, and 682 to 140 mg/L, respectively. Firmness increased during the storage time, while total soluble solids (TSS, around 17.4 °Brix) and total phenolic compounds (TP, around 14.21 mg/100 ml) showed no significant changes with CEO concentrations. Coatings containing 0.5% and 0.75% CEO significantly prevented fungal growth on the samples at least for 3 weeks and 3 months, respectively. Optimization proved that 1-week cold storage and 0.43% CEO could dramatically meet 80% of the research targets including maximum nutritional quality and freshness, as well preventing microbial spoilage. It was concluded that coating the pomegranate arils by PG and selecting an appropriate concentration of the CEO could considerably increase shelf life, marketability, and nutritional quality of pomegranate arils at a suitable and acceptable level.

The effect of grape seed protein hydrolysate on the properties of stirred yogurt and viability of Lactobacillus casei in it

In this study, the effect of grape seed protein hydrolysate (GPH) on the physicochemical and sensory properties of stirred yogurt was evaluated. At first, the antioxidant properties and degree of hydrolysis (DH) of GPH were determined using the microbial protease enzymes (alcalase and flavourzyme), the results showed that alcalase enzyme can produce GPH with higher DH and antioxidant properties (p < .05). Also, increasing the hydrolysis time had a positive effect on these properties (p < .05). The DH, free radical scavenging DPPH, and ferric reducing power for GPH by alcalase at 30 min was 21.51%, 88.68%, and 0.33 μmol ferrous/ g, respectively. Therefore, this treatment was used for further experiments. In the next part, the mentioned GPH was added to the stirred yogurt with three concentrations (0.5, 1.5, and 1.5%) and physicochemical properties and viability of Lactobacillus casei and sensory properties were measured during 15 days of storage. The results showed that the GPH treatment had higher pH, viscosity, and texture firmness and less acidity and syneresis compared with the control sample (p < .05). Also, in these samples, the decreasing trend of L. casei viability was slower than the control treatment during the storage period (p < .05). In most parameters, better results were observed with increasing the concentration GPH and all the treatments were acceptable in terms of sensory properties. Therefore, by producing yogurt containing GPH, a new functional food can be provided for consumers of dairy products, which in addition to the desired taste, good nutritional properties can be also achieved from its consumption.

Investigating the properties of PLA-nanochitosan composite films containing Ziziphora Clinopodioides essential oil and their impacts on oxidative spoilage of Oncorhynchus mykiss fillets

The present study aimed to investigate the impact of polylactic acid (PLA) integrated with nanochitosan (NC) composite film and Ziziphora Clinopodioides essential oil (ZCEO) on oxidative spoilage of rainbow trout fillets during a 9-day refrigeration period. For this purpose, first, six degradable films including T1: PLA, T2: PLA + NC, T3: PLA + NC + 1% ZCEO, T4: PLA + NC + 1.5% ZCEO, T5: PLA + 1% ZCEO, and T6: PLA + 1.5% ZCEO were prepared. Next, the properties of the films were investigated. The results of the mechanical tests showed that ZCEO decreased the tensile strength and increased the elongation at the break of the PLA films. However, adding NC improved the mechanical characteristics of the PLA film. The outcomes of physical tests including moisture content (14.02%), solubility (17.41%), water vapor permeability (1.14 × 10-7 g s-1 m-1 Pa-1), and oxygen transmission rate (21.54 cm3.mm/m2.24 hr) showed that adding 1% ZCEO improved the film physical characteristics. Nevertheless, by adding 1.5% concentration EO to the PLA film, the values of water vapor permeability, porosity (according to the scanning electron microscopy), and turbidity increased and cross-sectional pores were observed. Moreover, the films had high antioxidant properties (84.33%). In the next step, the effects of the mentioned films on the oxidative spoilage of rainbow trout fillets were investigated. The results of the chemical analysis in PLA film with the EO compared with the control treatment revealed the increasing trend of oxidation indices, in general. Moreover, increasing the concentration yielded better results such that all treatments containing EO showed satisfactory results up until the storage period ends. In most cases, adding NC affected the mentioned characteristics positively, and the best results were observed in T4 and then in T3. However, based on economics and the better mechanical and physical properties of T3, the film can be applied as an active packaging in fishery products.

Active coatings of thermoplastic starch and chitosan with alpha-tocopherol/bentonite for special green coffee beans

The quality of green coffee beans (GCBs) is possibly affected by storage conditions. Edible polymer coatings for GCBs can help preserve flavors and improve shelf life of GCBs. This study aimed to incorporate α-tocopherol, a powerful antioxidant, in thermoplastic starch [TPS] and chitosan [TPC] and determined the best cavitation energy (960-3840 J·mL-1) using an ultrasonic probe. Then, we evaluated the incorporation of bentonite (0% and 2% m/m) and α-tocopherol (0% and 10% m/m) in the best energy cavitation/biopolymer combination. The TPS and TPC coatings demonstrated good adherence to the GCBs, measured by surface energy. The dispersion of α-tocopherol in TPC, with cavitation energy 960 J·mL-1, promoted greater stability (greater zeta potential), thereby increasing antioxidant activity by 28% compared to TPS, therefore, was selected for a second stage. Incorporation of 2% bentonite into the TPC, with 10% α-tocopherol, resulted in a 3.7 × 10-10 g·m-1·s-1·Pa-1 water vapor permeability, which is satisfactory for prevented of moisture gain during storage. The compressive load showed values of 375 N to the non-coated GCB and around 475 N with the insertion of coatings to the GCB. Thus, a TPC/α-tocopherol/bentonite combination, dispersed with 960 J·mL-1 energy, was highly effective in the development of biopolymeric coatings for the GCBs.

Effect of the nanoencapsulated sour tea (Hibiscus sabdariffa L.) extract with carboxymethylcellulose on quality and shelf life of chicken nugget

In this study, the antioxidant properties of sour tea extract (Hibiscus sabdariffa L.) were investigated in both free and nanoencapsulated forms to increase the quality and shelf life of chicken nugget during a 9-day refrigerated storage period. For this purpose, the extract was prepared using ultrasound and quantities of phenolic and anthocyanin compounds, and antioxidant properties (DPPH free radical scavenging, FRAP) of extract was examined. The results showed that the value of phenolic compounds and anthocyanin compounds were 626.57 mg/g gallic acid and 379.11 µg/ml, respectively, and the extract had high antioxidant activity. Maltodextrin-whey protein concentrate was used for nanoencapsulation of the extract. Then, to investigate the effect of sour tea extract (free and nanoencapsulated forms) with carboxymethylcellulose (CMC) on quality and shelf life of chicken nugget, five treatments, including T1: control, T2: CMC, T3: CMC +1,000 ppm extract, T4: CMC +1,000 ppm nano extract; and T5: CMC +TBHQ, were prepared. First, physicochemical properties of nugget were measured. The results showed that CMC and sour tea extract reduced oil uptake, moisture content, frying percentage, frying efficiency, and soft texture of fried chicken nugget, and overall the best results were observed in CMC treatment with both extract and nano-extract (p < .05). Then, peroxide value (PV), total volatile nitrogen base (TVB-N), thiobarbituric acid (TBA), and sensory indexes were evaluated in treatments stored at refrigerator for 9 days. The results showed that sour tea extract has antioxidant properties and coating of extract increased its antioxidant properties as nugget containing 1,000 ppm the nanoencapsulated sour tea extract with CMC delayed oxidative spoilage and organoleptic changes of chicken nugget (p < .05). Therefore, it seems that the nanoencapsulated sour tea extract with CMC can be used as a natural preservative in meat and meat products.

The effect of encapsulated plant extract of hyssop (Hyssopus officinalis L.) in biopolymer nanoemulsions of Lepidium perfoliatum and Orchis mascula on controlling oxidative stability of soybean oil

The aim of this study was to investigate the effect of encapsulation method on antioxidant properties of Hyssop (Hyssopus Officinalis L.) extract. The extracts of the Hyssop were obtained by ultrasound assisted techniques, and the amount of phenolic compounds was 117.43 ± 9.22 (mg of gallic acid per 100 g of extract). The antioxidant activity of extracts in concentrations of 100, 200, 300, and 400 ppm was measured using DPPH free radical scavenging method and compared with 100 ppm of TBHQ synthetic antioxidants. The results showed that by increasing in concentration of the extract, the antioxidant activity of the extract increased. The Lepidium perfoliatum seed gum and Orchis mascula were chosen as coating material. Encapsulation was performed by emulsion production method. The antioxidant effects of nanocapsules in oil during 40 days of storage at 60°C were measured, which increased the oxidation of oil over time. The lowest amount of oil oxidation during storage compared to control samples was observed in samples containing nano encapsulated Hyssop extract due to reducing in release rate of the extract during storage and more protection of the extract. The results of this study suggest that encapsulation is an effective way to increase the antioxidant activity of the extract and could be increased the shelf life of edible oils with natural antioxidants.

Effects of encapsulated rosemary extract on oxidative and microbiological stability of beef meat during refrigerated storage

In this study, the effect of rosemary extract in two free and encapsulated forms to increase the shelf life of beef meat during a 28-day refrigerated storage period was investigated. For this purpose, rosemary was extracted using different extraction methods including ultrasound, solvent, and supercritical fluid extraction. The amount of phenolic compounds, antioxidant properties (free radical scavenging capacity of DPPH radical, ferric reducing antioxidant power), and antimicrobial activity of rosemary extract against pathogenic bacteria were evaluated. According to the results, the highest amount of phenolic compounds, antioxidant, and antimicrobial activity was observed in rosemary extracted by ultrasound method that used for next study (p < .05). In order to encapsulation of the rosemary extract, basil seed gum and soybean protein isolate separately and in combination form (1:1 w:w ratio) were used as carriers. Based on the particle size, zeta potential, and encapsulation efficiency tests, the best carriers were soybean protein isolate that used as a carrier for encapsulation. Then, to investigate the effect of rosemary extract to increase the shelf life of beef meat, 5 treatments including control, rosemary extract with concentrations of 800 ppm and 1,600 ppm, and nano-capsulation form of it with 800 ppm and 1,600 ppm concentrations were selected and they were periodically evaluated for chemical and microbial analysis (peroxide value, Thiobarbituric acid, color index, pH, and total viable count). The results showed that rosemary extract has an antimicrobial and antioxidant properties which could increasingly delay microbial spoilage and lipid oxidation of beef meat fillets, nano-capsulation form of rosemary could increase these qualities. The best results were observed in nano-capsulation of rosemary extract with 1,600 ppm (p < .05) as well as increased the shelf life of fillets till 21st day. Therefore, it seems that encapsulated rosemary extract could be used as a natural preservative in beef meat and meat products.