Optimizing the ultrasonic extraction of polyphenols from mango peel and investigating the characteristics, antioxidant activity and storage stability of extract nanocapsules in maltodextrin/whey protein isolate.

In this study, the extraction and nanoencapsulation of mango peel extract (MPE) were investigated to enhance its stability and preserve its antioxidant properties. Initially, using the central composite design (CCD)-response surface methodology (RSM), optimal conditions for the extraction of MPE via an ultrasonic system were determined to be a temperature of 10.53 °C, a time of 34.35 min, and an ethanol concentration of 26.62 %. Subsequently, the extracted extract was spray-dried and nanoencapsulated using three types of coatings: maltodextrin, whey protein isolate (WPI), and their combination. The results showed that nanoencapsulation led to a significant improvement in the stability of phenolic compounds in the extract during storage compared to free extract. Furthermore, capsules prepared with the combined coating exhibited the highest levels of phenolic compounds and antioxidant activity. Therefore, it can be concluded that nanoencapsulation can serve as an effective method for preserving the bioactive properties of MPE.

Development and Characterization of Antioxidant and Antibacterial Films Based on Potato Starch Incorporating Viola odorata Extract to Improve the Oxidative and Microbiological Quality of Chicken Fillets during Refrigerated Storage.

In this research, the antioxidant and antibacterial activities of active films based on potato starch containing Viola odorata extract (VOE) were investigated both in vitro and in chicken fillets. The VOE was added to the starch film formulation at 0, 1, 2, and 3% (w/v). The results showed that by increasing the extract level, the total phenol content and antioxidant and antibacterial activity of the films against Escherichia coli, Staphylococcus aureus, and Salmonella typhimurium improved remarkably. The results of the meat tests indicated the significant antioxidant and antimicrobial activity of active films containing different levels of VOE in chicken fillets, and a direct relationship was observed between the concentration of the extract and the functional activity of the films, so with the increase in the concentration of the extract in the films, the rate of lipid oxidation and growth of microorganisms in the chicken fillets decreased significantly during the storage period, and less volatile nitrogen bases, metmyoglobin, and oxidation products were produced in the fillets. In general, the results of this research demonstrated that an active film based on potato starch containing VOE (especially 2 and 3% levels) has the ability to extend the oxidative and microbiological shelf life of chicken fillets during cold storage for at least eight days.

Preparation and Application of Active Bionanocomposite Films Based on Sago Starch Reinforced with a Combination of TiO2 Nanoparticles and Penganum harmala Extract for Preserving Chicken Fillets.

The aim of this study was to develop sago starch-based bionanocomposite films containing TiO2 nanoparticles and Penganum harmala extract (PE) to increase the shelf life of chicken fillets. First, sago starch films containing different levels of TiO2 nanoparticles (1, 3, and 5%) and PE (5, 10, and 15%) were prepared. The barrier properties and antibacterial activity of the films against different bacteria strains were investigated. Then, the produced films were used for the chicken fillets packaging, and the physicochemical and antimicrobial properties of fillets were estimated during 12-day storage at 4 °C. The results showed that the addition of nano TiO2 and PE in the films increased the antibacterial activity against gram-positive (S. aureus) higher than gram-negative (E. coli) bacteria. The water vapor permeability of the films decreased from 2.9 to 1.26 (×10-11 g/m·s·Pa) by incorporating both PE and nano TiO2. Synergistic effects of PE and nano TiO2 significantly decreased the oxygen permeability of the sago starch films from 8.17 to 4.44 (cc.mil/m2·day). Application results of bionanocomposite films for chicken fillet storage at 4 °C for 12 days demonstrated that the films have great potential to increase the shelf life of fillets. The total volatile basic nitrogen (TVB-N) of chicken fillets increased from 7.34 to 35.28 after 12 days, whereas samples coated with bionanocomposite films increased from 7.34 to 16.4. For other physicochemical and microbiological properties of chicken fillets, similar improvement was observed during cold storage. It means that the bionanocomposite films could successfully improve the shelf life of the chicken fillets by at least eight days compared to the control sample.

Preparation and characterization of an intelligent film based on fish gelatin and Coleus scutellarioides anthocyanin to monitor the freshness of rainbow trout fish fillet.

In this study, a pH-sensitive indicator based on fish gelatin and Coleus scutellarioides anthocyanin extract (CSAE) was prepared and characterized. Films were prepared using the solvent casting method and different levels of CSAE, including 10 ml (CSG1), 20 ml (CSG2), and 30 ml (CSG3), and 0 ml (CSG0) as a control sample. The mechanical, optical, and pH sensing of active films and the release of anthocyanins from the films were investigated. The relationship between the total volatile basic nitrogen (TVB-N) of fish fillets and a* color index of films was studied. By incorporation of CSAE, the flexibility of films increased, while the tensile strength and UV-Vis light transmittance through the films decreased (p < .05). The films containing the CSAE had a darker, yellowish, and reddish color than the control film. There was a significant relationship between the pH variation and the film color. The films had a purple color at acidic pH, and their color changed to green at an alkaline pH, indicating the sensitivity of the produced films to pH changes. There was a significant relationship between the TVB-N value of fish fillets and the a* index of the film during the 16 h storage time. The results showed that by increasing TVB-N values of the fillets, the a* color index decreased, and the films' color changed from purple to colorless. In summary, the active films prepared with fish gelatin and CSAE could be used as pH-sensitive intelligent packaging to display the freshness of fishery products.

Fabrication and characterization of a smart film based on cassava starch and pomegranate peel powder for monitoring lamb meat freshness.

Nowadays, the development of pH-sensitive smart edible films using biopolymers and natural plant extracts (especially those rich in anthocyanins) has attracted much attention. Therefore, in this study, the intelligent edible film was produced and characterized using cassava starch and pomegranate peel powder (PPP) and the possibility of using production films to monitor the freshness of lamb meat. The smart films were prepared using different concentrations of PPP (2, 4, 6, and 8% w/w) and the solvent casting method. The results showed that the incorporation of PPP had a significant effect on the mechanical parameters of the starch films. With increasing the levels of PPP, the color of the films became darker and redder. Increasing the PPP levels also led to an increase in total phenol content (TPC) (from 0 to 13 mg GAE (gallic acid equivalent)/g) and antioxidant activity (from 0% to 70% DPPH (1,1-diphenyl-2-picryl hydrazyl) radical scavenging) of the produced films (p < .05). The intelligent film was used in the lamb meat packaging, and the color of the film changed from red to green during the storage period at 25°C. The amount of total volatile basic nitrogen (TVB-N) in the meat could be detected by color changes of the intelligent films. Finally, this study demonstrated that the film based on cassava starch and PPP could be used as an intelligent and pH-sensitive film to monitor the freshness of meat and meat products.

Assessment of the effect of marination with broccoli (Brassica oleracea var. italica) juice and balsamic vinegar on tenderness and quality of beefsteak.

Due to the increasing demand for natural foods with fewer artificial additives, broccoli is considered by the consumers and researchers due to its taste, nutritional values and biochemical components. Therefore, this research was conducted to investigate the effect of broccoli juice and balsamic vinegar on the physicochemical and textural attributes of the beefsteak aimed at tenderizing it and decreasing the ageing period. Experiments were carried out through marinating the beefsteak with three different treatments containing 3.00 units protease g-1 beefsteak of broccoli juice and 10.00% (v/w) of balsamic vinegar during 48 hr storage at 4.00˚C. A significant reduction in pH and Warner-Bratzler shear force as well as the increase in myofibrillar fragmentation index and myofibrillar protein solubility were obtained showing that the beefsteak was tendered in the presence of broccoli juice and broccoli juice+balsamic vinegar. Scanning electron microscopy images showed the destruction of endomysium collagen and sarcolemma areas of muscle filaments in the above-mentioned treatments. The electrophoretic analysis of isolated myofibrillar proteins indicated that the rate of troponin-T breakdown was quicker in all treatments compared to the control and its degradation was progressively obvious with 20.00 and 28.00 kDa protein bands in mentioned treatments. Based on the results, marinades of broccoli juice and balsamic vinegar could be utilized as a beneficial additive for improving beefsteak tenderness.

Prediction of top round beef meat tenderness as a function of marinating time based on commonly evaluated parameters and regression equations.

This study investigates the influence of 24-hr marination (with different plant extracts and vinegar) at refrigerated conditions on commonly evaluated physicochemical and textural attributes, including pH, water-holding capacity (WHC), collagen solubility, moisture, drip loss, and shear force values of beef meat. The results reflected the appropriate correlation between each pair and indicated the efficiency of the household marination procedure to acquire more palatability and tender beef meat. Therefore, to predict beef meat tenderness by applying the Warner-Bratzler shear force (WBSF), a strong positive correlation with the drip loss (p < .01) and a notable negative correlation with the moisture content (p < .01) emphasized the importance of moisture improvement and shear force reduction in affecting tenderness of baked beef meat. The regression equations and R-squared values were revealed the favorable correlation between collagen solubility and WHC (y = 0.1035x-0.8431, R 2 = .98) as well as moisture and WBSF (y = -0.3297x + 102.58, R 2 = .99) in marinated beef meat. Electrophoresis patterns of isolated myofibrillar proteins disclosed remarkable degradation of myosin heavy chain (MHC), desmin, actin, and tropomyosin during the first day of aging. The noticeable ultrastructural destruction and connective tissue solubilization were observed by microscopy images. These outcomes were a good tenderness predictor be utilized in retailing and industrial scale.

The combined effect of asparagus juice and balsamic vinegar on the tenderness, physicochemical and structural attributes of beefsteak.

The adverse effects of chemical compounds have limited their usage despite their relative success in improving meat tenderness. Thus, natural tenderizers have attracted attention. The present study aimed to evaluate the tenderization effects of asparagus (Asparagus officinalis L.) juice and balsamic vinegar on beefsteak; marination at 4 °C for 48 h significantly increased the water-holding capacity, total protein solubility, myofibrillar fragmentation index and hydroxyproline content but significantly decreased the pH value, Warner-Bratzler shear force, and energy to the peak rates (P < 0.05). Scanning electron microscopy images and electrophoresis findings revealed extensive degradation of connective tissues and changes in protein band patterns, respectively. The tenderness of the beefsteak samples was optimum by applying 25% asparagus juice, and 25% asparagus juice + 10% balsamic vinegar. Therefore, marinade solutions containing asparagus juice and balsamic vinegar can be considered as natural tenderizing agents in formulation of seasonings and sauces to promote tenderness in tough beefsteak and possibly improve other quality-related properties.