Effect of tannic acid and kiam wood extract on lipid oxidation and textural properties of fish emulsion sausages during refrigerated storage

Dietary hazelnut skin prevents lipid oxidation in lamb enriched in omega-3 polyunsaturated fatty acids

The aim of this study was to investigate the effect of partially replacing maize with hazelnut skin and linseed, alone or in combination, on the oxidative stability of lamb. Forty lambs were randomly assigned to 4 treatments and fed: a conventional cereal-based diet (C), or the same diet with 15 % of hazelnut skin (HS), or 8 % of extruded linseed (LS), or 7.5 % of hazelnut skin plus 4 % of linseed (H + L) as partial replacement of maize. After 60 days of feeding trial, lambs were slaughtered, and hydrophilic antioxidant capacity and fat-soluble vitamins content were evaluated in fresh meat. Colour stability, lipid and protein oxidation were assessed during 7 days of refrigerated storage. Dietary combination of hazelnut skin and linseed increased the content of tocopherols (P < 0.001) and of n-3 polyunsaturated fatty acids (PUFA n-3; P < 0.001), while reducing lipid oxidation (TBARS value) during 7 days of storage (P < 0.001). Feeding lamb with hazelnut skin and/or linseed did not affect meat hydrophilic antioxidant capacity, colour stability, nor the formation of hydroperoxides, thiols, or carbonyls (P > 0.05). These results suggest that vitamin E provided by hazelnut skin contributed to delay lipid oxidation in meat, despite the higher concentration of n-3 PUFA.

Cocktail Sausage Supplemented With Whole Tomato Powder Encapsulated in Chia Seed Mucilage (Salvia hispanica L.) by Lypholization: The Color, Sensory, Textural Properties, and Oxidation Stability of Sausage

The deterioration of meat products is significantly influenced by the oxidation of lipids. The addition of antioxidants is one of the accepted methods to retard lipid oxidation. The goal of this research was to encapsulate tomato powder with chia seed mucilage by lyophilization. Tomato powder and chia seed mucilage were used as the wall material at three ratios 1:1 (T1:C1), 2:1 (T2:C1), and 1:2 (T1:C2). The particle size, encapsulation efficiency, rheology, and solubility index of the beads were assessed. Three sausage samples, including the control, 3% w/w tomato powder (TPsample), and 6% w/w bead (EnTPsample), were produced. The color, texture, peroxide, thiobarbituric acid, and sensory parameters of the sausage were analyzed during storage. The results showed that T2:C1 had a maximum encapsulation efficiency (44.71%) with particle size (172.31 nm). T1:C1 had a highly significant value in the solubility index (90.09% w/w), but for the viscosity parameter, T1:C2 had a maximum value among the samples. FTIR and X-ray diffraction analyses demonstrated successful encapsulation in all samples. The water holding capacity (6.92% w/w), hardness (2992.5 g), and gumminess (2772.3 g) were the highest, but cooking loose (10.98% w/w) the lowest in the EnTPsamples. Higher color and odor scores were recorded for the EnTPs. In addition, the encapsulated tomato powder had a significantly (p < 0.05) lower peroxide value (7.34 mEq/kg) and thiobarbituric acid (2.09 mg MDA/kg) in the sausages than in the other samples. In conclusion, the incorporation of EnTPsample as a polyphenol component in cocktail sausages is more advantageous than TP alone.

Effect of the addition of black garlic on the quality parameters of jerked beef meat with pork

The objective of this work was to evaluate the effects of the replacement of nitrite by natural antioxidants from black garlic (BG) on the quality parameters of jerked beef meat with pork for 60 days. Four formulations were prepared: control, 0.02% of sodium nitrite in brine curing, w/v (CON); 1.5% BG in brine curing, w/v (ASU); 1.5% BG in dry curing, w/w (ASS); and 1.5% of BG in the brine curing, w/v and 1.5% of BG in dry curing, w/w (ASUS). Nutritional composition, pH, water activity, shear force, fatty acid profile, color, and oxidative stability of the formulations were analyzed. The addition of BG did not affect the nutritional composition, pH, water activity, shear force, and fatty acid profile. On the other hand, it resulted in lower weight loss after centrifugation and lower values of L* and a*. TBARS values from the 30th day of storage were lower in the ASUS formulation, while carbonyl compounds at all times were lower than in the CON formulation. Results suggest that BG was an efficient alternative to nitrite in controlling protein oxidation during storage. Thus, the use of pork for the manufacture of jerked beef can be an alternative, and black garlic can be applied as a natural additive to the replacement of nitrite. In addition, black garlic was efficient in improving the oxidative stability of the jerked beef meat with pork.

Impact of antioxidant potential of rohu (Labeo rohita) swim bladder gelatin hydrolysate on oxidative stability, textural and sensory properties of fish sausage enriched with polyunsaturated fatty acids

The impact of rohu swim bladder gelatin hydrolysate (SBGH) at different levels on textural, sensory, oxidative, and microbial properties of polyunsaturated fatty acids enriched rohu fish cooked sausages (PUFA-RFS) were investigated in the current study. SBGH addition enhanced the lightness values of PUFA-RFS compared to both control sausages (without SBGH and with butylated hydroxyanisole (BHA) (P > 0.05). PUFA-RFS added with 3% SBGH exhibited higher hardness, cohesiveness, and gumminess throughout the storage duration at both 4 °C and -20 °C temperatures when compared to other sausages counterparts. PUFA-RFS added with SBGH displayed lower PV, TBARS, and total microbial counts than the control sausages. Furthermore, PV, TBARS, and total microbial count values of sausage decreased with an increase in SBGH level, indicating retardation in lipid oxidation and microbial growth by SBGH in a dose-depended manner. Nevertheless, sausage added with 3% SBGH had higher overall acceptability than other sausage counterparts. Therefore, SBGH could retard lipid oxidation and improves textural properties of PUFA-enriched fish sausage.

Effects of Maillard reaction products on myoglobin-mediated lipid oxidation during refrigerated storage of carp

Lipid oxidation is the major cause of quality deterioration in freshwater fish, especially mediated by myoglobin (Mb). This study aimed to investigate the antioxidant mechanism of Maillard reaction products (MRPs) in Mb-mediated lipid oxidation in common carp (Cyprinus carpio). MRPs exhibited promising antioxidant and antimicrobial capacities based on the reduced content of peroxide and thiobarbituric acid-reactive substances and inhibited microbial growth. MRPs inhibited the oxidation of Mb by lowering the transfer from oxymyoglobin to metmyoglobin and improving the stability of heme iron. The correlation analysis showed that MRPs regulated the formation of free radicals by maintaining the reduced structure of Mb and the integrity of heme iron, and also directly inhibited the formation of oxidation products in a chain radical reaction. The texture and electronic nose analysis indicated that MRPs could delay the structural disruption and flavor deterioration of surimi. Therefore, MRPs could effectively inhibit Mb-induced lipid oxidation and further control the resulting changes in the flavor and texture of surimi.

Performance and meat quality in pigs fed hydrolysable tannins from Tara spinosa

This study aimed to assess the effect of dietary tara (Tara spinosa (Feuillée ex Molina) Britton & Rose) hydrolysable tannins on performance and meat quality of finishing pigs. Twenty barrows (crossbred PIC × Piétrain; age: 125 ± 5 d; bodyweight: 60.8 ± 3.89 kg) were randomly assigned to two groups and fed ad libitum for 7 weeks a control diet (CON) or a diet supplemented with 10 g/kg of tara tannins (TAT), respectively. No differences (P > 0.10) on growth performance and carcass traits were observed between the two groups. Meat fatty acid profile was not affected (P > 0.10) by the diet, but the content of C22:5 n-3 tended to be lower (P = 0.079) in TAT pork. Dietary tannins tended to reduce (P = 0.095) meat cholesterol. The diet had no effect (P > 0.10) on fat-soluble antioxidant vitamins, hydrophilic antioxidant capacity, catalase activity, and glutathione peroxidase activity. Superoxide dismutase activity tended to be lower (P = 0.087) in TAT meat than in CON meat. Dietary tannins did not affect (P > 0.10) backfat and meat color development during 6 days of refrigerated storage, but TAT meat tended to be darker (P = 0.082). Meat from pigs fed tara tannins showed lower (P = 0.028) hydroperoxides content and a tendency toward lower conjugated dienes (P = 0.079) and malondialdehyde (P = 0.084) contents. Also, dietary tannins delayed lipid oxidation in meat subjected to oxidative challenges such as catalysis and cooking (P < 0.05). The positive effect of dietary tara hydrolysable tannins on lipid oxidation was likely due to their antioxidant and anti-inflammatory capacity, but it may have been mitigated by the high α-tocopherol content in meat.

Exploring the impact of various cooking techniques on the physicochemical and quality characteristics of camel meat product

OBJECTIVE

The objective of this study was to evaluate the effects of four different cooking techniques viz: boiling, grilling, microwave, and frying; on the physicochemical characteristics of camel meat.

METHODS

Protein composition and their degradation as well as biochemical and textural changes of camel meat as influenced by cooking methods were investigated.

RESULTS

The highest cooking loss (52.61%) was reported in microwaved samples while grilled samples showed the lowest cooking loss (44.98%). The microwaved samples showed the highest levels of lipid oxidation as measured by thiobarbituric acid reactive substances, while boiled samples showed the lowest levels (4.5 mg/kg). Protein solubility, total collagen, and soluble collagen content were highest in boiled samples. Boiled camel meat had lower hardness values compared to the other treated samples. Consequently, boiling was the more suitable cooking technique for producing camel meat with a reduced hardness value and lower lipid oxidation level.

CONCLUSION

The camel meat industry and camel meat consumer can benefit from this research by improving their commercial viability and making consumers aware about the effects of cooking procedures on the quality of camel meat. The results of this study will be of significance to researchers and readers who are working on the processing and quality of camel meat.

Whey Protein-Tannic Acid Conjugate Stabilized Emulsion-Type Pork Sausages: A Focus on Lipid Oxidation and Physicochemical Features

The purpose of this study was to investigate the oxidative stability and physicochemical properties of pork emulsion sausages with whey protein-tannic acid conjugate and native whey protein. Over the course of 21 days, the thiobarbituric acid reactive substances (TBARS) of sausages containing a whey protein-tannic acid conjugate were lower than those of sausages with regular whey protein (p < 0.05). Kinetically, sausage containing the whey protein-tannic acid conjugate (k = 0.0242 day^-1) appeared to last longer than sausage containing regular whey protein (k = 0.0667 day^-1). The addition of the whey protein-tannic acid conjugate had no effect on product texture because there was no difference in hardness, springiness, cohesiveness, or water-holding capacity between the control and treated samples at Day 0 (p > 0.05). Scanning electron microscopy revealed that, at Day 21, the control sausage exhibited emulsion coalescence, as evidenced by an increase in the number of oil droplets and large voids, but not the whey protein-tannic acid conjugate-added sausage. There was no variation in the L*, a*, and b* values of the sausages when the whey protein-tannic acid conjugate was added (p > 0.05). However, there was a little increase in ΔE value in the treated sample. Thus, the whey-protein-tannic acid conjugate appeared to stabilize the lipid and physicochemical properties of the sausages by lowering the rate of TBARS production, retaining texture, water-holding capacity, and color, as well as by minimizing lipid coalescence during refrigerated storage.

Feeding hazelnut skin to lambs delays lipid oxidation in meat

This study aimed to investigate the effect of dietary hazelnut skin (HNS), a by-product of confectionery industry, on the oxidative stability of lamb meat. Twenty-two finishing lambs were randomly assigned to 2 groups and fed ad libitum for 56 days on different concentrate-based diets: one control and one experimental, in which 150 g/kg of corn was replaced by HNS. After slaughter, the fat-soluble vitamins content and hydrophilic antioxidant capacity were assessed in fresh meat, as well as color, lipid and protein stability over 7 days of shelf-life trial. Dietary HNS increased (P < 0.001) the tocopherols content of meat and reduced (P < 0.001) lipid oxidation during 7 days of refrigerated storage. Meat from lambs fed HNS showed different (P < 0.05) instrumental color parameters. No diet effect (P > 0.05) was observed on the development of metmyoglobin, hydroperoxides, thiol groups, and carbonyl groups. Feeding HNS to lambs improves the oxidative stability of raw meat by delaying lipid oxidation thanks to the antioxidant molecules (tocopherols and phenolic compounds) contained in this by-product.

Muscle protein oxidation and functionality: a global view of a once neglected phenomenon

Muscle is a highly organized apparatus with a hierarchicmicrostructure that offers the protection of cellular components againstreactive oxygen species (ROS). However, fresh meat immediately postmortem andmeat undergoing processing become susceptible to oxidation due to physicaldisruption and the influx of molecular oxygen. Upon the activation byendogenous prooxidants, oxygen species are rapidly produced, and bothmyofibrillar and sarcoplasmic proteins become their primary targets. Direct ROSattack of amino acid sidechains and peptide backbone leads to proteinconformational changes, conversion to carbonyl and thiol derivatives, andsubsequent aggregation and polymerization. Interestingly, mild radical andnonradical oxidation enables orderly protein physicochemical changes, which explainswhy gels formed by ROS-modified myofibrillar protein has improved rheologicalproperties and binding potential in comminuted meat and meat emulsions. Theincorporation of phenolic and other multi-functional compounds promotes gelnetwork formation, fat emulsification, and water immobilization; however,extensive protein modification induced by high levels of ROS impairs proteinfunctionality. Now recognized to be a natural occurrence, once-neglectedprotein oxidation has drawn much interest and is being intensively studiedwithin the international community of meat science. This review describes thehistory and evolution of muscle protein oxidation, the mechanism andfunctionality impact hereof, and innovative oxidant/antioxidant strategies tocontrol and manipulate oxidation in the context of meat processing, storage,and quality. It is hoped that the review will stimulate in-depth discussion of scientificas well as industrial relevance and importance of protein oxidation and inspirerobust international collaboration in addressing this global challenge.&nbsp;

Application of soymilk skin as sausage wrapping for improving lipid oxidation

Yuba, the soymilk skin, was developed as edible films for sausage. Yuba (Y) were prepared with added pine-needle extract (YP) and employed to wrap sausage. Physical and mechanical properties and lipid oxidation of sausages were compared to sausages made with commercial collagen casing (C). Y films showed better transparency, oxygen-barrier properties, and UV-light barrier properties than C films (p < .05). Particularly, the addition of pine-needle extract increased DPPH activities from 31 to 48% and total phenol content from 7.52 to 14.64 mg gallic acid/g. Regarding application for sausage wrapping, Y (2.35%) and YP (2.66%) wrapped sausages with better protection against water loss during cooking compared to sausages made from C (5.84%). Especially, YP (3.57 MDA mg/kg) showed better protection against lipid oxidation for sausages than Y (4 MDA mg/kg) and C (4.62 MDA mg/kg) on day 6 after refrigerated storage. Yuba films could be employed as potential alternatives to gelatin films for manufacturing sausages.

Combination of Flos Sophorae and chili pepper as a nitrite alternative improves the antioxidant, microbial communities and quality traits in Chinese sausages

The main issue remains finding a nitrite alternative able to provide its multiple functions. Flos Sophorae exerts antioxidant and prebiotic actions, chili pepper has potent coloring capacity, thus this study investigated whether combination of Flos Sophorae and chili pepper could address the multiple activities of nitrite in Chinese sausages. Dry-fermented sausages were prepared: control and four treatments added with 150 mg/kg sodium nitrite (Nit), 0.2% Flos Sophorae (FS), 1% chili pepper (CP), and combination of 0.2% Flos Sophorae and 1% chili pepper (FS + CP). Results indicated that FS, CP and FS + CP had higher moisture, antioxidant activity and numbers of beneficial Staphylococcus and yeasts Candida, and lower numbers of Escherichia coli and harmful fungi, while FS had lower redness and harder texture than control. Their combination inhibited the declines of capsanthin and antioxidant capacity with ripening time, further improved microbiological communities compared with CP, and resulted in higher redness, similar color score and bacterial community, less lipid oxidation and softer texture compared with Nit. These results suggested that Flos Sophorae in combination with chili pepper could replace the nitrite's contribution to red curing color and microbiological communities, and effectively hinder lipid oxidation in Chinese sausages.

Mexican oregano essential oils as alternatives to butylated hydroxytoluene to improve the shelf life of ground beef

Oregano essential oils from Lippia berlandieri Schauer (Lb) and Poliomintha longiflora Gray (Pl) were tested against the antioxidant butylated hydroxytoluene (Bht) to evaluate effects on the shelf life of ground beef (GB) over 7 days of storage at 4°C. The treatments were GB1 = GB control, GB2 = GB +100 mg/kg of Bht, GB3 = GB +100 mg/kg of Lb, and GB4 = GB +100 mg/kg of Pl. Lightness, redness, hardness, and springiness showed differences (p < .05) between treatments and days interaction, which serve as indicators of ground beef preserved quality and consumer acceptance. Mesophilic, psychrophilic, and lactic acid bacteria numbers and antioxidant activity showed differences (p < .05) for treatments and days. Sensory attributes showed no differences between treatments. The oregano oils may provide extended shelf life for packaged meat products treated with these natural additives and hence may be used for ground beef preservation.

Influence of Reheating Methods and Frozen Storage on Physicochemical Characteristics and Warmed-Over Flavor of Nutmeg Extract-Enriched Precooked Beef Meatballs

The effects of convection-oven precooking, frozen storage (−18 °C/ two months) and four different reheating methods—namely, boiling, pan-roasting, convection oven and microwave oven on pH, color, texture, antioxidant activity and warmed-over flavor of beef meatballs were investigated. In this study, four kinds of beef meatballs were prepared: with added butylated hydroxyl toluene (0.02% BHT, M1); with nutmeg extract (0.02%, M2); with nutmeg powder (0.02%, M3) and control (no antioxidant). Addition of (0.02%) nutmeg extracts in beef meatballs M2 resulted in a significant (p < 0.05) decrease in lipid and protein oxidation, hardness and gumminess values after convection oven precooking. Again, M2 reheated by microwave oven significantly (p < 0.05) reduced cooking loss, gumminess, springiness, rancid flavor, saltiness and burnt taste and increased oxidative stability, redness and adhesiveness with the chewiness intensity and overall acceptability compared to control, M1 and M3. Conclusively, the addition of nutmeg extracts (0.02%) as a natural plant antioxidant to precooked beef meatballs can result in reduced lipid and protein oxidation levels, stabilized color and texture values and improved overall acceptance after reheated by microwave oven during two months of frozen storage.

Characterization of fish sausage manufactured with combination of sunflower oil and fish oil stabilized with fish roe protein hydrolysates

The present study aimed to determine the effect of adding protein hydrolysates obtained after 30, 60, and 90 min enzymatic hydrolysis of fish roe on properties of silver carp sausages enriched with fish oil during storage at 4 °C for 30 days. Properties of the fortified sausages were determined by assessment of primary and secondary oxidation, fatty acid composition, microbial spoilage, texture, and organoleptic properties. The results indicated that the hydrolysates could retard oil oxidation and microbial spoilage and preserve n - 3 fatty acids in fish sausages during the refrigerated storage. Also, they rendered firmer microstructure with smaller oil droplets to the sausages. Fish sausages fortified with the hydrolysates were lighter and exhibited better textural and sensory properties. It can be concluded that enzymatic hydrolysates from discarded fish roe can be added to fish sausages containing fish oil to retard oil oxidation and microbial spoilage and improve sausage properties.

Addition of seaweed powder and sulphated polysaccharide on shelf_life extension of functional fish surimi restructured product

This study aimed to investigate the performance of equal amounts of edible green seaweed, Ulva intestinalis powder (2.77 g kg^-1), and its sulphated polysaccharide ([USP], 0.5 g kg^-1, based on the extraction yield from U. intestinalis powder) on the proximate compositions, lipid oxidation, pH, colour, textural properties, cooking yield and sensory attributes of fish-surimi restructured products during storage at - 18 °C as compared with the control. Results showed incorporation of two functional components resulted in lower TBARS values compared with the control over 6 months (P ≤ 0.05). The USP incorporated fingers showed the least moisture loss over 6 months (P < 0.05). Textural properties for two functional fingers remained relatively stable from month 0 to month 6, while the hardness increased significantly (P < 0.05) in the control fingers (67 to 80 N). Additionally, the sensory attributes of all formulated fingers were judged acceptable; however, the USP containing fingers were preferred by the sensory panelists, due to their juicy texture as a result of less cooking loss comparing with others. In conclusion, this study suggests the potential use of such natural marine ingredients to maintain the quality and to extend the shelf life of surimi-based products with beneficial health effects.

Antioxidant activity of vine tea (Ampelopsis grossedentata) extract on lipid and protein oxidation in cooked mixed pork patties during refrigerated storage

To prevent oxidation and maintain the quality of meat products, it is essential to add antioxidants. The aim of this work was to investigate the antioxidant activity of vine tea (Ampelopsis grossedentata) extract (VTE) and evaluate the effects of VTE on the quality characteristics and lipid and protein oxidation of cooked mixed pork patties during refrigerated storage. VTE had a significant DPPH radical scavenging activity, and its IC50 was 15.35 µg/ml. VTE-treated mixed pork patties had a better texture than that of the control group (p < 0.05). VTE could significantly inhibit an increase in the TBARS value and the formation of carbonyl compounds (p < 0.05), and the inhibition was stronger than that of the butylated hydroxytoluene (BHT) group (p < 0.05), while the amount of sulfhydryl groups significantly decreased (p < 0.05). The color of VTE itself made the mixed pork patties darker (p < 0.05), but this did not affect the sensory scores and overall acceptability of the VTE-treated patties, indicating the VTE can be incorporated into mixed pork patties. The scanning electron microscopy (SEM) results showed that the VTE inhibited the oxidation of the cooked mixed pork patties during refrigerated storage. These findings may be significant to helping extend the shelf life of meat products.

Effect of Allium hookeri Root on Physicochemical, Lipid, and Protein Oxidation of Longissimus Dorsi Muscle Meatball

The antioxidant effects of Allium hookeri root (AHR) were investigated by evaluating lipid and protein oxidation in meatballs during refrigerated storage at 4±1℃. AHR was mixed at concentrations of 0.5% (w/w, T2) and 1% (w/w, T3) with minced longissimus dorsi muscle. Meatballs containing AHR (T2 and T3) were compared to those containing 0.05% (w/w) ascorbic acid (T1) as a reference and without antioxidant as a control. The 2-thiobarbituric acid reactive substances (TBARS) value, disulfide bond formation, carbonyl contents, and volatile basic nitrogen (VBN) value of T2 were lower than those of the control during storage (p<0.05). The pH values of T2 and T3 were higher than that of the control (p<0.05). Texture profile analysis of T2 revealed a lower value compared to the control (p<0.05). Therefore, the VBN value, TBARS value, disulfide bond formation, and carbonyl content in meatball containing AHR were lower than those of the control meatball. These results indicate that AHR improves the quality of meat products and functions as an antioxidant.

Degradation of myofibrillar, sarcoplasmic and connective tissue proteins by plant proteolytic enzymes and their impact on camel meat tenderness

Inside round muscles (Adductor) from camels treated with bromelain or ficin or papain at 50 or 100 ppm were subsequently stored at 4 °C for 4 days to study the impact on quality attributes, protein degradation and textural changes. Results revealed that papain (100 ppm) treated camel meat showed higher drip loss and lower water holding capacity compared to other treatments. Total protein, sarcoplasmic protein solubility, trichloroacetic acid (TCA)-soluble peptides and soluble collagen were higher in papain and bromelain treated samples at 100 ppm compared to other treatments. Electrophoretic profile of whole camel meat, isolated sarcoplasmic and myofibrillar proteins depicted a noticeable degradation of various proteins in enzyme treated samples, with papain and bromelain (100 ppm) displaying pronounced effect. Meat treated with papain at 100 ppm displayed lower hardness and shear force (P < 0.05). Thus, enzymes treatment at 100 ppm displayed good potential to tenderize camel meat with the papain being more effective among all.

The effect of repeated freeze-thaw cycles on the meat quality of rabbit

<p>We investigated the effect of repeated freeze-thaw cycles on the quality of rabbit meat. Twenty-five Hyla rabbits were slaughtered using standard commercial procedures. A freeze-thaw procedure—i.e., seven days frozen at –18°C followed by thawing at 4°C for 12h— was repeated 5 times, and 9 <em>Longissimus thoracis et lumborum</em> muscles were randomly selected at pre-set cycles (0, 1, 2, 3, and 5). The <em>Longissimus lumborum</em> muscles were used to determine meat quality parameters, while the <em>Longissimus thoracis</em> muscles were used for chemical analysis. During the repeated freeze-thaw process, muscle pH, redness, hardness, and water holding capacity gradually decreased, whereas meat lightness and yellowness gradually increased. The amount of total volatile basic nitrogen significantly increased (<em>P</em>&lt;0.05) and exceeded the threshold value for frozen meat after 5 repeated freeze-thaw cycles. The metmyoglobin proportion, thiobarbituric acid-reactive substances (TBARS) and protein carbonyl content in rabbit meat samples increased with a higher number of freeze-thaw cycles (<em>P</em>&lt;0.05), and the proportions of these compounds were positively correlated. During the repeated freeze-thaw process, extractable haeme iron levels significantly decreased (<em>P</em>&lt;0.05), and non-haeme iron levels markedly increased (<em>P</em>&lt;0.05). An sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis indicated that the degradation of both water- and salt-soluble proteins was more prevalent in samples subjected to higher numbers of freeze-thaw cycles. Additionally, a principal component analysis identified good correlations between physicochemical properties (TBARS, protein carbonyl levels and metmyoglobin content) and quality parameters (thawing loss, redness, lightness and hardness). Taken together, we conclude that the repeated freeze-thaw process can strongly affect rabbit meat quality as well as its physicochemical properties.</p>

Effect of 6-gingerol on physicochemical properties of grass carp (Ctenopharyngodon idellus) surimi fortified with perilla oil during refrigerated storage

BACKGROUND

Surimi is produced from deboned fish muscle through washing to remove blood, lipids, sarcoplasmic proteins and other impurities. There is an increasing interest in the fortification of surimi with ω-3 polyunsaturated fatty acids because of their health benefits. However, lipid oxidation should be considered as an important factor during storage. Hence, in this study, the quality properties and oxidative stability of surimi fortified with 30 g kg^-1 perilla oil (PO), or 5 g kg^-1 6-gingerol (GI) or their combination (PO+GI) was investigated.

RESULTS

Perilla oil significantly improved whiteness of surimi gel, but negatively influenced its gel strength, water holding capacity (WHC) and texture. However, there was no significant difference in texture properties among GI, PO+GI and control groups. During the whole storage period, GI and PO+GI groups had higher gel strength and WHC than control and PO groups. Moreover, lower thiobarbituric acid reactive substances (TBARS), total volatile basic nitrogen (TVB-N), carbonyl content and total plate count (TPC) were observed in GI group compared with other groups.

CONCLUSION

Perilla oil and 6-gingerol could be applied together to effectively fortify surimi qualities. Additionally, 6-gingerol could prevent lipid and protein oxidation and microbial growth of surimi during refrigerated storage. © 2017 Society of Chemical Industry.

Protective effects of Momordica grosvenori extract against lipid and protein oxidation-induced damage in dried minced pork slices

The experiment was conducted to assess the protective effects of Momordica grosvenori extract (MGE) against lipid and protein oxidation-induced damage in vacuum-packed dried minced pork slices stored at room temperature for 21days. Antioxidant activity of MGE was evaluated by measuring its radical scavenging activities and reducing power with progressive concentrations from 40 to 200g/L. MGE was added to the dried minced pork slices at 7, 10 or 15g/100g. Results showed that inclusion of MGE in dried minced pork slice significantly delayed the formation of hexanal, thiobarbituric acid-reactive substances and carbonyls and reduced the sulfhydryl loss in a dose-dependent manner (P<0.05), indicating that MGE exerted a protective effect against lipids and protein oxidation. Concomitantly, an intense increase of redness and loss of lightness and yellowness was found to take place (P<0.05), though it exhibited little negative effects on the sensory properties of slices. Mogrosides, the main bioactive components in M. grosvenori, decreased primarily during processing while they were relatively stable during storage under vacuum condition, room temperature. All these results demonstrated MGE had great potential as a natural antioxidant used in meat products.

Effects of brown seaweed polyphenols, α-tocopherol, and ascorbic acid on protein oxidation and textural properties of fish mince (Pagrosomus major) during frozen storage

BACKGROUND

Frozen storage of minced fish is currently one of the most important techniques to maintain its functional properties. However, some deterioration does occur during frozen storage and cause quality loss. The effects of brown seaweed polyphenols, α-tocopherol, and ascorbic acid on lipid and protein oxidation and textural properties of red sea bream (Pagrosomus major) during 90 days of frozen storage at -18 °C were investigated.

RESULTS

All added antioxidants at 1 g kg-1 resulted in significantly lower thiobarbituric acid-reactive substances (TBARS) compared to the control during the 45 days of frozen storage. The antioxidants were also effective in retarding protein oxidation concerning to total sulfhydryl content and protein carbonyl content. Brown seaweed polyphenols and α-tocopherol significantly retarded the inactivation of Ca2+ -ATPase activity during the first 45 days, whereas ascorbic acid had no such effect. The antioxidant activity showed either an invariable or decrease trend after 45 days storage. Adding antioxidants had a significant effect on the breaking force of the gels during the frozen storage period.

CONCLUSION

These results indicate that brown seaweed polyphenols and α-tocopherol can be used to prevent oxidative reactions and thus maintain the structure of the gel formed by fish mince during frozen storage. © 2016 Society of Chemical Industry.

CO2 Plant Extracts Reduce Cholesterol Oxidation in Fish Patties during Cooking and Storage

Cholesterol oxidation products (COPs) in foods may pose risks for human health. Suitable antioxidants can reduce the formation of COPs in industrial products. Consumer awareness of food additives has brought a need for more natural alternatives. This is the first study on the effects of supercritical CO₂ extracts of rosemary, oregano, and an antimicrobial blend of seven herbs, tested at two levels (1 and 3 g/kg fish), against cholesterol oxidation in patties made of a widely consumed fish species, Atlantic salmon (Salmo salar), during baking and storage. Cholesterol oxidation was reduced by the extracts as indicated by lowered levels of 7α-hydroxycholesterol, 7β-hydroxycholesterol, and 7-ketocholesterol, which were quantified by GC-MS. The total amount of COPs was smaller in all of the cooked samples containing the plant extracts (<1 μg/g extracted fat) than in the cooked control (14 μg/g). Furthermore, the plant extracts exhibited protective effects also during cold storage for up to 14 days.