Review of fish protein hydrolysates: production methods, antioxidant and antimicrobial activity and nanoencapsulation.

Marine products have gained popularity due to their valuable components, especially protein, despite generating significant waste. Protein hydrolysates are widely recognized as the most effective method for transforming these low-value raw materials into high-value products. Fish protein hydrolysate (FPH), sourced from various aquatic wastes such as bones, scales, skin, and others, is rich in protein for value-added products. However, the hydrophobic peptides have limitations like an unpleasant taste and high solubility. Microencapsulation techniques provide a scientific approach to address these limitations and safeguard bioactive peptides. This review examines current research on FPH production methods and their antioxidant and antibacterial activities. Enzymatic hydrolysis using commercial enzymes is identified as the optimal method, and the antioxidant and antibacterial properties of FPH are substantiated. Microencapsulation using nanoliposomes effectively extends the inhibitory activity and enhances antioxidant and antibacterial capacities. Nevertheless, more research is needed to mitigate the bitter taste associated with FPH and enhance sensory attributes.

Investigating the possibility of increasing the microbial and oxidative stability of silver carp burgers using hydrolyzed protein of watermelon seeds.

In this study, watermelon seeds (Citrullus lanatus) protein hydrolyzed (WSPH) was produced using microbial enzymes Alcalase and Protamex. Then, the effect of different concentrations of WSPH (0, 1, 2, and 3%) on the quality of the silver carp (Hypophthalmichthys molitrix) burger during refrigerated storage (4 ± 1 °C) was investigated. According to the results, WSPH by alcalase had significantly higher degree of hydrolysis and antioxidant activity (p < 0.05) and it was used for burger tests. The results showed that, the addition of WSPH was able to reduce the microbial, chemical spoilage and sensory score during 16 days compared to the control, and with increasing the concentration of WSPH, better results were observed (p < 0.05). According to the chemical, microbial and sensory indicators, WSPH at 3% could increase the shelf life of fish burgers up to 8 days compared to the control, and this treatment was within the permissible quality limit until the end of the refrigerated storage.

Investigating the effect of type of fish and different cooking methods on the residual amount of polycyclic aromatic hydrocarbons (PAHs) in some Iranian fish: A health risk assessment.

The aim of this study was to assess the level of PAHs and associated health risks in different types of fish cooked with different methods, using the MSPE-GC/MS technique (magnetic solid phase extraction with gas chromatography/mass spectrometry). The limits of detection (LODs), limits of quantification (LOQs) and recovery percentages ranged from 0.1 to 0.63 µg/kg, 0.3-1.89 µg/kg, and 93.7 to 102.6%, respectively. The results showed that the mean of Æ©PAHs in all samples was 20.31 ± 6.60 µg/kg. Additionally, PAH4 and BaP levels in all samples were 4.58 ± 1.40 and 1.08 ± 0.36 µg/kg, respectively, which were below the European Union (EU) standard level (12 and 2 µg/kg, respectively). The results showed that among 5 types of fish, starry sturgeon had highest average total PAHs (13.24 ± 1.84 µg/kg), while Caspian Sea sprat had the lowest average total PAHs (1.24 ± 0.8 µg/kg). In terms of cooking methods (charcoal-grilled fish, fried fish and oven-grilled fish), charcoal-grilled fish had the highest average total PAH level at 25.41 ± 7.31 µg/kg, while the lowest average total PAH was found in the raw fish sample at 16.44 ± 4.63 µg/kg. The Monte Carlo Simulation was used to determine the 95% ILCRs (Incremental Lifetime Cancer Risk) due to ingestion of fish. The results showed that the ILCR for adults was 2.85E-9, while for children it was 1.32E-8. Therefore, based on these findings, it can be concluded that the consumption of fish cooked with different methods does not pose a risk to human health in terms of the amount of PAHs (ILCR < 1 × 10-4).

Assessment of virulence factors and antimicrobial resistance among the Pseudomonas aeruginosa strains isolated from animal meat and carcass samples.

BACKGROUND: Pseudomonas aeruginosa bacteria are emerging causes of food spoilage and foodborne diseases. Raw meat of animal species may consider a reservoir of P. aeruginosa strains. OBJECTIVES: The present survey was done to assess the prevalence, antibiotic resistance properties and distribution of virulence factors among the P. aeruginosa strains isolated from raw meat and carcass surface swab samples of animal species. METHODS: Five hundred and fifty raw meat and carcass surface swab samples were collected from cattle and sheep species referred to as slaughterhouses. P. aeruginosa bacteria were identified using culture and biochemical tests. The pattern of antibiotic resistance was determined by disk diffusion. The distribution of virulence and antibiotic resistance genes was determined using polymerase chain reaction. RESULTS: Forty-seven of 550 (8.54%) examined samples were contaminated with P. aeruginosa. The prevalence of P. aeruginosa in raw meat and carcass surface swab samples were 6.57 and 12%, respectively. P. aeruginosa isolates showed the maximum resistance rate toward penicillin (87.23%), ampicillin (85.10%), tetracycline (85.10%), gentamicin (65.95%) and trimethoprim (57.44%). The most commonly detected antibiotic resistance genes were BlaCTX-M (53.19%), blaDHA (42.55%) and blaTEM (27.65%). The most commonly detected virulence factors was ExoS (42.55%), algD (31.91%), lasA (31.91%), plcH (31.91%) and exoU (25.53%). CONCLUSIONS: Meat and carcass surface swab samples may be sources of resistant and virulent P. aeruginosa, which pose a hygienic threat in their consumption. However, further investigations are required to identify additional epidemiological features of P. aeruginosa in meat and carcass surface samples.

The effect of hydrolyzed sesame meal protein on the quality and shelf life of hamburgers during refrigerated storage.

In this study, to improve the quality and shelf life of hamburgers, sesame meal protein hydrolysates (SPH) were produced using two enzymes of alcalase and flavourzyme and then four hamburger treatments: T1: control (10% soybean), T2: 1% SPH + soybean 9%, T3: 2% SPH + soybean 8%, and T4: 3% SPH + soybean 7% were prepared. Physicochemical properties were analyzed at the beginning of the storage period; microbial and chemical quality was evaluated at intervals of 0, 4, 8, 12, and 16 days. The results of SPH showed that alcalase enzyme can produce a SPH with a higher antioxidant properties (DPPH, FRAP, and beta-carotene-linoleic acid) (P < 0.05); therefore, this SPH was used for hamburger properties. According to the results, with the addition of SPH, moisture, fat, texture firmness decreased, protein, and brightness increased (P < 0.05), and all treatments had the allowable range. SPH replacement with soybean slowed down the increasing trend of oxidation and microbial spoilage (P < 0.05). In general, better results were observed in T3 and T4, which had a permissible range chemical and microbial index until the end of the storage period, as well as these treatments inhibited the growth of Staphylococcus aureus and Escherichia coli. Only T3 was approved by the evaluators.

Effect of clover sprouts protein hydrolysates as an egg substitute on physicochemical and sensory properties of mayonnaise.

Mayonnaise is a semi-solid oil-in-water emulsion that in addition to eggs other stabilizers and thickeners are used as emulsifiers for better stability. Although eggs are an important ingredient in the production of mayonnaise, the health problems associated with the use of eggs is increasing due to their high cholesterol content. The aim of this study was to evaluate the feasibility of clover sprout protein hydrolysates (CSPH) to replace eggs for the production mayonnaise. First, CSPH was produced using alcalase and flavourzyme enzyme, and in order to find the best enzyme, the degree of hydrolysis (DH) and protein recovery (PR) were determined. Then four mayonnaise treatments included, T1: control (egg 9%), T2: egg 6%+ CSPH 3%, T3: egg 3%+ CSPH 6%, T4: egg 0%+ CSPH 9% was prepared and the stability, viscosity, physicochemical, textural, and sensory properties of mayonnaise was investigated. The samples containing CSPH showed that CSPH had high essential amino acids, CSPH from alcalase enzyme had higher amounts of protein, DH, PR, and increasing hydrolysis time had a positive effect on these parameters (p < .05); therefore, CSPH from alcalase enzyme was used for the production mayonnaise. The stability, viscosity, firmness, adhesion of texture, and pH increased with increasing CSPH, while the brightness, acidity, and sensory score of the samples decreased (p < .05). In general, T3 had an acceptable quality in terms of the studied characteristics, but sensory score in T4 could not be confirmed. Hence, by replacing eggs with CSPH up to 6%, mayonnaise with appropriate physicochemical and sensory properties can be produced. Therefore, the formulation egg 3%+ CSPH 6% is an appropriate choice to produce mayonnaise for consumers who are on a restricted diet to eat foods containing eggs.

Use composite coating of chitosan-chia seed gum enriched with microliposomes of Bay laurel essential oil to increase the shelf life of quail fillets.

In this study, the effect of composite chitosan-chia seed coating (CH-CG) with Bay laurel (Laurus nobilis) essential oil (BE) in two forms including free and nanocapsulated on the shelf life of quail fillets during the 16-day refrigeration (4 ± 1℃) period was investigated. For this purpose, first, BE was extracted by Clevenger apparatus. Then, nanoliposomes BE were produced, and the properties of BE and nanoliposomes BE were investigated. In order to investigate the shelf life of quail, 6 treatments were produced including 1: control (C), 2: CH-CG, CH-CG+BE at 800 ppm, 3: CH-CG+BE at 1600 ppm, 4: CH-CG+nano BE at 800 ppm, 5: CH-CG+nano BE at 1600 ppm, and periodically chemical parameters (peroxide value, free fatty acid, total volatile basic nitrogen, texture firmness, and chewing ability) and microbial (total viable bacteria (TVC) and psychrotrophic bacteria), and the effect of different treatments on control in Escherichia coli and Staphylococcus aureus inoculated populations in quail was also investigated. The BE had high antioxidant and antimicrobial properties. The particle size and microencapsulation efficiency of BE nanoliposome were 98.3 nm and 75.95%, respectively. The results of chemical and microbial analysis showed that in general, the coating with essential oil slowed down the increasing trend of oxidation and microbial indices compared to the control treatment and nanocapsulation of essential oil has increased its antimicrobial and antioxidant properties (p < .05). At the end of storage period, in all tests, treatments of 3, 4, and 5 had the allowed microbial and chemical range and they also inhibited the growth of these bacteria (p < .05). Overall, considering the higher sensory score of treatment 4 and economic efficiency, it seems that this treatment can be used as a natural preservative in the meat industry.

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.

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.

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.

Carboxymethyl cellulose-agar biocomposite film activated with summer savory essential oil as an antimicrobial agent.

Carboxymethyl cellulose (CMC)-agar biocomposite film was developed by a solvent casting method and the effects of summer savory essential oil (SSEO) at 0.5, 1.0 and 1.5% v/v on antimicrobial, microstructural, mechanical and optical properties as well as water sensitivity of the films were studied. Results showed that incorporation of SSEO into the biocomposite film developed active films with good growth inhibition activity against Gram-positive bacteria (S. aureus, B. cereus and L. monocytogenes) and less powerfully against Gram-negative bacteria (E. coli). Addition of the SSEO at 1.0 and 1.5% increased microstructural heterogeneity of the films and hence significantly (p < 0.05) increased water vapor permeability of the films while reducing their tensile strength. In contrast, mechanical flexibility and surface hydrophobicity of the films were significantly (p < 0.05) improved as a function of SSEO addition. The active films showed substantially lower swelling ratio compared to the CMC-agar film when 1.5% SSEO was added, but the transparency of the films was reduced. Finally, the results showed that SSEO can act as an antimicrobial agent in combination with CMC-agar film. However, it modifies properties of the film depending on the applied concentration.

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.

Modeling of drying kiwi slices and its sensory evaluation.

In this study, monolayer drying of kiwi slices was simulated by a laboratory-scale hot-air dryer. The drying process was carried out at three different temperatures of 50, 60, and 70°C. After the end of drying process, initially, the experimental drying data were fitted to the 11 well-known drying models. The results indicated that Two-term model gave better performance compared with other models to monitor the moisture ratio (with average R2 value equal .998). Also, this study used artificial neural network (ANN) in order to feasibly predict dried kiwi slices moisture ratio (y), based on the time and temperature drying inputs (x1, x2). In order to do this research, two main activation functions called logsig and tanh, widely used in engineering calculations, were applied. The results revealed that, logsig activation function base on 13 neurons in first and second hidden layers were selected as the best configuration to predict the moisture ratio. This network was able to predict moisture ratio with R2 value .997. Furthermore, kiwi slice favorite is evaluated by sensory evaluation. In this test, sense qualities as color, aroma, flavor, appearance, and chew ability (tissue brittleness) are considered.