Characterization of intelligent film based on chitosan/high-amylose starch and Portulaca oleracea L. flavonoids/anthocyanins/curcumin and its application in beef.

This work was motivated by the observation of the apparently not adequate trade conditions of the fresh, defrosted and processed Brazilian sardine (Sardinella brasiliensis) in the city of Sao Paulo-SP. Sardine samples were analysed for thiobarbituric acid reacting substances (TBARS) and total volatile base nitrogen (TVB-N). The samples were collected and analysed at three different times in the production chain: on landing at CEAGESP (the Central Warehouse Company of the State of Sao Paulo), while on sale at the street markets before the species-catching prohibition and while on sale at the street markets during the species-catching prohibition period (December-March). The following results were observed for the sardine landed at CEAGESP (mean ± standard deviation): TBARS= 0.18 ± 0.17 mg malondialdehyde (MDA)/ kg and TVB-N= 15.75 ± 2.39 mg/ 100 g. For the sardines collected at the street markets before the prohibition period, the results were TBARS= 0.82 ± 0.63 mg MDA/ kg and TVB-N= 27.06 ± 2.18 mg/ 100 g. The values detected for the samples collected at the street markets during the prohibition period were TBARS= 7.14 ± 5.36 mg MDA/ kg and TVB-N= 27.69 ± 2.80 mg/ 100 g. The results show a statistically significant difference between the TBARS values for the samples collected at CEAGESP and the ones collected at the street markets before the prohibition period and between the latter and the ones collected at the street markets during the prohibition period. On the other hand, a statistically significant difference was noticed between the TVB-N values for the sardines collected at CEAGESP and the ones collected at the street markets, but there was not any statistically significant difference between the samples collected at the street markets before and during the prohibition period. In unwashed brined sardines the following values were recorded: TBARS= 4.07 ± 1.22 mg MDA/ kg and TVBN= 44.32 ± 14.38 mg/ 100 g, while for the washed samples the results were TBARS= 1.25 ± 0.23 mg MDA/ kg and TVB-N= 39.63 ± 4.00 mg/ 100 g. For ripened sardine values of TBARS= 3.71 ± 0.77 mg MDA/ kg and TVB-N= 62.96 ± 9.33 mg/ 100 g were detected. TBARS values were also compared to available lysine and no significant correlation was found (R= 0.1732). Only the fresh sardines landed at CEAGESP showed acceptable condition for consumption.

Braised chicken is a popular meat product with an attractive appearance, delicious taste, and rich nutrition. High‐throughput sequencing technology (HTS) was utilized to comprehensively characterize the dynamics of the microbial community during processing and storage (4°C). The physicochemical properties (pH, moisture content, total volatile base nitrogen (TVB‐N), and the thiobarbituric acid reactive substances (TBARS)) and colony counts were also evaluated. The microbial community of braised chicken was different between processing and storage. Weissella and Psychrobacter were the dominant genera during processing; Acinetobacter, Pseudomonas, Enterobacter, Aeromonas, and Aneurinibacillus were the dominant genera in storage. The microbial counts (total viable count [TVC], Pseudomonas, LAB, and Enterobacteriaceae) decreased gradually during hot working processing, but increased during storage. After the warranty, TVC and Enterobacteriaceae counts exceeded the limit for cooked meat products. TBARS and TVB‐N increased from 0.089 to 0.400 mg/kg and 0.52 to 2.03 mg/kg, respectively, during processing and storage, and TVB‐N content exceeded the limit of cooked meat products after the warranty. Spearman's correlation analysis showed that Pseudomonas, Enterobacter, and Aeromonas were significantly positively correlated with the spoilage index (TVB‐N and TBARS). Amino acid metabolism and carbohydrate metabolism were also significantly positively correlated with them，indicating that Pseudomonas, Enterobacter, and Aeromonas may be the main microorganisms that cause spoilage of braised chicken. This study revealed the possible spoilage microorganisms of braised chicken during processing and storage, which was helpful to improve the quality and safety of braised chicken.

The current study explores the changes in beef quality following partial freezing and during superchilled storage, alongside chilled storage comparisons. Kinetic models were developed to predict changes in colour difference (∆E), thiobarbituric acid-reactive substances (TBARS), total volatile basic nitrogen (TVB-N), drip loss and firmness. Beef samples were partially frozen in an air blast freezer at -30 °C for 9 min prior to storage at -5 °C, -4 °C, -2.8 °C, -1.8 °C. Chilled beef samples were directly stored at 2 °C and 6 °C without partial freezing. All samples were stored for 21 days. The lightness (L*), redness (a*), yellowness (b*) and colour difference (∆E) were significantly lower in superchilled storage samples compared to chilled storage samples. The pH of beef samples increased gradually over time (p < 0.05). TBARS, TVB-N and drip loss increased while firmness decreased with the increase in storage time in both storage conditions (p < 0.05). Overall, beef quality was affected by both storage duration and temperature. Firmness followed the first order kinetic model; drip loss, TVB-N, TBARS and colour difference (∆E) fitted the zero-order kinetic model. Temperature dependence was adequately modelled using Arrhenius-type equation with the activation energy values of 110.111, 52.870, 68.553, 119.480, 47.301 kJ/mol for drip loss, firmness, TBARS, TVB-N and colour difference (∆E), respectively. The models demonstrated strong predictive performance, with RMSE and MAPE values within ±10%. The developed kinetic models successfully predicted quality changes within the -5 °C to 6 °C temperature range.

To meet the need for food products to be safe and fresh, smart food packaging that can monitor and give information about the quality of packaged food has been developed. In this study, pH-sensitive films with sago starch and various anthocyanin concentrations of Brassica oleracea also known as red cabbage anthocyanin (RCA) at 8, 10, 12, and 14% (w/v) were manufactured using the solvent casting process. Investigation of the physicochemical, mechanical, thermal, and morphological characteristics of the films was performed and analysed. The response of these materials against pH changes was evaluated with buffers of different pH. When the films were exposed to a series of pH buffers (pH 3, 5, 9, 11, and 13), the RCA-associated films displayed a spectacular colour response. In addition, the ability of the starch matrix to overcome the leaching and release of anthocyanins was investigated. Higher concentrations of RCA can maintain the colour difference of films after being immersed in a series of buffer solutions ranging from acidic to basic conditions. Other than that, incorporating RCA extracts into the starch formulation increased the thickness whereas the water content, swelling degree, tensile strength, and elongation at break decreased as compared to films without RCA. The immobilisation of anthocyanin into the film was confirmed by the FTIR measurements. The surface patterns of films were heterogeneous and irregular due to the presence of RCA extract aggregates, which increased as the extract concentration enhanced. However, this would not affect the properties of films. An increase in thermal stability was noted for the anthocyanin-containing films at the final stage of degradation in TGA analysis. It is concluded that RCA and sago starch formulation has great potential to be explored for food packaging purposes.

Using oxidation kinetic models to predict the quality indices of rabbit meat under different storage temperatures

Effect of atmospheric cold plasma treatment on ready-to-eat wine-pickled Bullacta exarata

Liver sausage is flavorful and highly nutritious. However, liver has a relatively short shelf life due to acceleration of oxidation in the presence of endogenous enzymes and metals. Powders derived from natural sources, including plants or fruits, are applied to meat products for inhibiting oxidation without adverse effects on their quality. Hence, this study investigated the effects of natural powders derived from green tea leaf (GTL), lotus leaf (LL), and kimchi (KC) on the quality and change in lipid oxidation and freshness of chicken liver sausages during two weeks of storage. Chicken liver sausages were manufactured with chicken breast (70%) and liver (20%), pork back fat (5%), iced water (5%), various additives, and GTL, LL, and KC [0 (control) or 1%]. They were processed in three batches. For determination of the quality characteristics of chicken liver sausages with various plant powders, pH, color, and texture properties were assessed. In addition, lipid oxidation and freshness using thiobarbituric acid reactive substances (TBARS) and total volatile basic nitrogen (TVBN) were analyzed at day 0 and week 2 of refrigerated storage. Higher values were obtained for pH and cooking yield in sausage samples with LL and KC powders than in samples with the other treatments. For a* values, the sausage samples with KC showed similar (p > 0.05) values, whilst others had significantly lower values than the control. The addition of the three powders to sausage samples induced an increase (p < 0.05) in hardness, gumminess, and chewiness. The addition of plant powders did not influence TBARS and TVBN of sausage samples at the initial stage. However, after two weeks of storage, significantly lower TBARS and TVBN values were observed, and the sausage with KC (p < 0.05) showed the lowest values of both TBARS and TVBN. The results showed the potential ability of the three powders to improve the quality and inhibit lipid oxidation in liver sausages. Particularly, the addition of KC did not adversely affect the a* values of sausage samples. The effects on sensory properties and inhibition mechanisms of GTL, LL, and KC in meat products should be further studied.

Given that the chemical composition of seafood species reflects the conditions characterizing their geographic area of origin, this study aims to describe and compare the nutritional composition of several seafood species marketed in Luanda (Angola) and in Faro (Portugal), namely octopus (Octopus sp.), large-eye dentex (Dentex macrophthalmus), hake (Merluccius sp.) and barracuda (Sphyraena guachancho). In addition, a sensory-based methodology (the Quality Index Method, QIM) was carried out and a set of physicochemical parameters (pH, total volatile basic nitrogen (TVBN) and thiobarbituric acid reactive substances (TBARS)) were determined to assess the degree of freshness and quality of the different species. The results showed that location significantly (t-test, p < 0.05) influences some parameters of the nutritional composition, viz. moisture, protein content and lipid content. Quality indexes (QI) resulting from sensory analyses using QIM schemes were less than five (out of a maximum of 16–19 demerit points) indicating seafood’s high quality. In terms of physicochemical quality parameters, the values of pH varied between 6.11 for octopus and 6.78 for large-eye dentex, TVBN content ranged from 5.4 mg N/100 g for octopus and 9.6 mg N/100 g for barracuda in Luanda, and TBARS concentrations varied between 0.43 mg MDA/kg for large-eye dentex in Faro and 2.09 mg MDA/kg for hake in Faro. For every species studied the values were well below acceptable limits for consumption considering EU regulations (25–35 mg N/100 g for TVBN) and literature (7-8 µg MDA/g for TBARS), both in Luanda and in Faro. This study provides original results about nutritional composition and sensory and physicochemical indicators of seafood freshness and quality for the studied species in Luanda.

This study investigated the changes in pH, water retention, color, texture characteristics, protein conformation, thiobarbituric acid reactive substances (TBARSs), total volatile basic nitrogen (TVB-N), and total plate count in reduced-fat sausages. It explored the quality differences between sausages with and without the addition of resistant starch during storage at 4 °C over a period of 1 to 30 days. The results indicated that TBARS and TVB-N values significantly increased (p < 0.05) with the extension of refrigeration time, and the α-helix and β-sheet structures were transformed into β-turn and random coil structures, leading to a significant decrease in the pH, L* and a* values, texture characteristics, and chewiness of all sausages, as well as a significant increase in storage loss and centrifugation loss. Under the same refrigeration time, the sausage with added resistant starch exhibited better water retention and texture characteristics compared to the treatment without resistant starch. Additionally, the TBARS and TVB-N values were significantly lower (p < 0.05) in the former. Therefore, the incorporation of resistant starch can effectively slow down the deterioration of gel properties and the increase in total bacterial count in reduced-fat sausages during refrigeration.

Meatballs were coated by gelatin-based mixes incorporated with potassium sorbate and rosemary extract. Coated samples were evaluated by free fatty acids (FFAs), thiobarbituric acid reactive substances (TBARS), and total volatile basic nitrogen (TVB-N) content. In addition, texture profile analysis (TPA) was performed to evaluate the textural features of meatballs. Uncoated sample as control along with 3 other samples coated by different formulations were stored in zipped plastic bags at +4 °C for 10 days. No significant difference was observed between samples regarding FFA and TBARS although coating with potassium sorbate showed suppressive effect on TVB-N initially. The starting pH of meatball was 6.22 and the coatings generally limited the change in pH compared to the control. Although significant differences in color were observed due to the color of coating itself, the coatings limited the variations in color to some extent. Other quality parameters were not improved much with the studied formulations. It is concluded that active edible coatings might be utilized in muscle foods for preservation and shelf-life extension if appropriately formulated and applied. Comprehensive studies are needed to determine the performance of carrier polymers in release of active ingredients and suitable formulations for every single group of food.

A study was conducted during 2016 to evaluate the effect of salt and mechanical drying on Pangasius at Central Institute of Fisheries Education, Andheri, Mumbai, India. In this study, the salted and unsalted Pangasius was mechanically dried at 60°C temperature and the quality of the dried Pangasius was evaluated. The quality parameters include the changes in proximate composition, physicochemical parameters [total volatile base nitrogen (TVBN), peroxide value (PV), free fatty acid (FFA), pH, thiobarbituric acid reactive substances (TBARS), salt, water activity], microbial enumeration (total viable count (TVC), Escherichia coli, Staphylococcus spp.) and sensory evaluation. The colour characteristics, percentage yield and storage stability of the product was also evaluated. From the results, it was observed that the protein and ash content of unsalted dried Pangasius was higher than salt dried Pangasius. From the results of physicochemical changes, it was observed that PV, FFA, TVBN, TBARS and salt content were higher in salt dried Pangasius. The TVBN, PV and salt content of salt dried Pangasius were 24.75 mg N 100 g-1, 4.17 meq O2 kg-1 fat and 14.55% respectively which were higher than the Unsaltd dried Pangasius. The salt dried Pangasius had higher L* value but lower a* and b* value than unsalted dried Pangasius. The unsalted dried Pangasius was unstable during storage whereas salt dried Pangasius was stable. Based on the results, it was concluded that salt drying is the most effective method of preservation for drying Pangasius at 60°C.

&lt;p&gt;The present study was carried out to prepare thyme essential oil (TEO) and ginger essential oil (GEO)-incorporated edible starch coating on buffalo meat to extend its refrigerated shelf-life. Edible coatings incorporated with antimicrobials can act as an active packaging system for the preservation of meat using biopolymers and plant-based essential oils. Buffalo meat samples were coated by hydrothermally treated starch solution incorporated with thyme and ginger essential oil at five different proportions (total of 2.5% of starch solution). A total of five treatments (S1, S2, S3, S4, and S5) along with two controls (S6 and S7) were subjected to microbiological [total viable count (TVC), &lt;italic&gt;Staphylococcus aureus&lt;/italic&gt; count, psychrotrophic bacteria count (PTC), and coliform count] and physico-chemical analyses such as thiobarbituric acid reactive substance (TBARS) value, total volatile basic nitrogen (TVBN) content, extract release volume (ERV), metmyoglobin (Met-Mb), pH, weight loss, and water activity at 0, 3, 6, 9, and 12 days of storage. These metrics were compared between days and between treatments. Compared with the uncoated control (S7), S4 decreased TVC by 2.60 log, and S5 decreased PTC, &lt;italic&gt;Staphylococcus aureus&lt;/italic&gt;, and coliform by 4.71 log, 1.18 log, and 3.01 log, respectively, in 12 days. S4 reduced TBARS and TVBN by 46.14% and 27.86%, respectively, while S5 increased the ERV by 40.94% in 12 days when compared to S7. Metmyoglobin content, pH, ERV, and TVBN were found to have a high correlation with TVC, while pH was found to have a high correlation with TVBN and ERV. It can be concluded that the increase in TEO concentrations on starch coating increases the ability of buffalo meat to resist microbiological as well as chemical spoilage.&lt;/p&gt;

To evaluate and predict the freshness of brined bream (Megalobrama amblycephala) fillets stored at different temperatures, changes in quality [nucleotide degradation products (IMP, HxR, Hx), K value, sensory assessment (SA), total aerobic counts (TAC), thiobarbituric acid reactive substances (TBARS), and total volatile base nitrogen (TVB-N)] were investigated. The Arrhenius model, back-propagation neural network (BP-NN), and radial basis function neural network (RBF-NN) were established and compared. The RBF-NN predicted changes of SA, TAC, K value, TVB-N, TBARS, and HxR of brined fillets during storage with relative errors all within ±5 %, while the BP-NN values were all within ±10 % (except for the values at day 2 for K value, day 2 and day 4 for HxR). For the Arrhenius model, the relative errors of TVB-N were all within ±10 %, and those of SA, TAC, K value, TBARS, and HxR ranged from 0.58 to 44.37 %. Thus, RBF-NN is a promising method for predicting the changes in the quality of bream during storage at 270–282 K.

The aim of the study was to evaluate quality of ready-to-cook (RTC) hilsa curry under not sealed pack as control, vacuum as T1, MAP-1 (50% CO2 &amp; 50% N2) as T2, and MAP-2 (40% CO2 , 30 N2 &amp; 30% O2) pack as T3 during storage at 4±1°C. For this purpose, pH, total volatile base nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS) and aerobic plate count (APC) of three samples from each treatment were analyzed at four days interval during 28 days of storage. The pH and TVB-N values of RTC hilsa curry were within the standard limit in all samples during the storage period. However, significantly (p &lt;0.05) lower values were observed on and after the 12th day for pH and 16th day for TVBN in all samples compared to the control. TBARS gradually increased from the 4th day for all samples except vacuum packaged sample. However, significantly (p &lt;0.05) lower TBARS were observed in the vacuum and MAP-1 samples on and after the 8th day of storage compared to the control and MAP-2 samples. APCs gradually increased from the initial value of 5.25 log CFU/g with time in all samples. However, significantly (p &lt;0.05) lower APCs were observed on and after the 16th day of storage in all samples compared to the control sample. The APCs exceeded the 7 log CFU/g, which is considered as the upper acceptable limit on approximately 16th day for the control, 24th day for vacuum, 22nd day for MAP-1, and 20th day for MAP-2 sample. Therefore, the vacuum packaging demonstrated the better results, which the superstores can utilize conveniently to display RTC hilsa curry with prolonged shelf life. J. Bio-Sci. 29(2): 71-79, 2021 (December)

Background: Seafood such as fish is an integral part of human nutrition and an excellent source of protein. However, their short shelf life is quite challenging for the food industry. Objectives: This study was carried out to investigate the effects of nano-gelatin coating embedded with thymol and nisin on the chemical quality indices of rainbow trout fillets during 16 days of storage at 4°C. Methods: The fillets were randomly divided into six groups, including control (C), gelatin (G), nano-gelatin (NG), nano-gelatin + thymol (NG-T), nano-gelatin + nisin (NG-N), and nano-gelatin + nisin and thymol (NG-T-N). The chemical quality of fish samples was assessed by performing pH, thiobarbituric acid reactive substance (TBARS), peroxide value (PV), free fatty acid (FFA), and total volatile basic nitrogen (TVB-N) analyses every four days. Results: The results revealed the stunning effect of nisin and thymol addition to the nano-gelatin coating on all chemical quality indices. Besides, PV, TBARS, and FFA analyses showed that nano-gelatin containing thymol significantly decreased lipid oxidation in fish fillet samples (P &lt; 0.05). The lowest amounts of PV (8.33 meq oxygen/kg oil), TBARS, and FFA were recorded for NG-T-N. The best results in the TBARS test (P &lt; 0.05) were observed in NG-T-N, followed by NG-T (1.45 and 1.69 mg of malonaldehyde/kg of tissue, respectively), and similar results were recorded for FFA analysis. On day 16, the lowest amounts of TVB-N were measured for NG-T-N, followed by NG-N and NG-T (26.13, 29.86, and 38.26 mg N/100 g, respectively). Both nisin and thymol reduced the TVB-N and increased the shelf life, and the best results were observed in groups treated with nisin and thymol simultaneously. However, the application of gelatin and nano-gelatin coating without nisin and thymol was ineffective in improving the chemical quality of samples, and they must be used with nisin and/or thymol. Conclusions: Gelatin nanogel embedded with thymol and nisin can be utilized to enhance the chemical quality and shelf life of fish fillets.