Effect of plant extracts on lipid oxidation during frozen storage of minced fish muscle

The aim of the study is to determine the effect of pomegranate seed extract (PSE) and grape seed extract (GSE) addition to chub mackerel minced muscle on lipid oxidation during frozen storage. Each extract was added to minced fish muscle at 2% concentration and then stored at ?18 °C for 3 months. The effect of plant dietary fibres to control lipid oxidation was compared with untreated samples (control). Formation of lipid hydroperoxides and thiobarbituric acid‐reactive substances (TBARS) was significantly inhibited by PSE and GSE addition when compared with control. Both extracts significantly retarded lipid oxidation according to the results of TBARS. A significant reduction of L* (lightness), a* (redness) and b* (yellowness) values was detected during frozen storage. GSE added samples had the highest redness and the lowest lightness and yellowness. However, samples with PSE showed the lowest redness and highest yellowness and h° (hue angle) values. The results from this study suggest GSE is a very effective inhibitor of primary and secondary oxidation products in minced fish muscle and have a potential as a natural antioxidant to control lipid oxidation during frozen storage of fatty fish.     

Effect of lipid oxidation and frozen storage on muscle proteins of Atlantic mackerel (Scomber scombrus)

The effect of storage on the lipids and proteins in Atlantic mackerel stored for up to 24 months at ?20 and ?30 °C was studied. Traditional methods including the peroxide value, thiobarbituric acid‐reactive substances (TBARS) and a reverse phase HPLC method were used to determine the primary and secondary lipid oxidation products. All tests showed an increase in lipid oxidation products with storage time and at a higher storage temperature of ?20 °C compared with samples stored at ?30 °C. Antioxidants had a significant effect (P < 0.01) on the inhibition of lipid oxidation, as shown by the reduction in peroxide value and hydroxides, and malondialdehyde formation. Similarly, deterioration of protein structure and functionality in mackerel stored for 3, 6, 12 and 24 months was greater at ?20 than ?30 °C. ATPase activity in the myosin extract of Atlantic mackerel showed a significant decrease (P < 0.01) with progressive frozen storage. Protein solubility in high salt concentration (0.6 M NaCl) decreased (P < 0.01) during storage at both ?20 and ?30 °C but was greater at ?20 °C. Interestingly, antioxidants BHT, vitamin C and vitamin E protected the proteins against complete loss of ATPase activity and protein solubility to a significant level (P < 0.01) for up to 1 year at ?20 °C compared with samples stored without antioxidants. This study confirms the deleterious effect of lipid oxidation products on protein structure and function in frozen fatty fish. © 2002 Society of Chemical Industry     

Glazing herring (Clupea harengus) fillets with herring muscle press juice: effect on lipid oxidation development during frozen storage

In this study, fish muscle press juice, PJ, was evaluated as an antioxidative liquid for glazing of fish fillets prior to frozen storage. PJ has in previous studies efficiently protected fish mince lipids against haemoglobin‐mediated oxidation. Frozen herring fillet were glazed with water, PJ or 50 mm phosphate buffer of the same pH as herring PJ (6.5). Over 52 weeks, peroxide value (PV), TBA‐reactive substances (TBARS), rancid odour and colour were monitored. From 26 to 52 weeks, water‐glazed fillets were significantly (P < 0.05) more oxidised compared to fillets glazed with PJ or buffer, most clearly shown by PV and TBARS data. The protective effects of both PJ and buffer compared to water could indicate a role, for example, of the physiological ionic strength. The finding that PV became elevated in PJ which was frozen stored alone in a thin layer indicates that PJ stripped from, for example, trace lipids and haemoglobin would provide better protection.     

Influence of skinning on lipid oxidation in different horizontal layers of herring (Clupea harengus) during frozen storage

This study was conducted to evaluate the effect of skinning and of compositional differences on the oxidative stability of various horizontal layers from herring (Clupea harengus) during frozen storage. Herring fillets, with and without skin, were stored at -18°C for 0, 3, 9, 16 and 28 weeks. After each storage period, the fillets were divided horizontally into three layers: ‘under skin’, ‘middle part’ and ‘inner part’. Each layer was then extracted for total lipids, in which peroxide value (PV), absorbance at 234 nm (A₂₃₄) and 268 nm (A₂₆₈) as well as lipid-soluble fluorescent oxidation products (FP) were measured. Prior to storage, the fat content, fatty acid pattern and α-tocopherol were also analysed. During storage of skinless fillets, the under skin layer increased most in PV, A₂₃₄, A₂₆₈ and FP (P<0·05), followed by the inner and middle parts. In fillets stored with skin, the high oxidation rate of the under skin layer lipids was suppressed, but this layer still gave rise to the highest responses. Firstly, these results point to the protective properties of the skin and, secondly, to the unfavourable composition of the under skin layer: a lot of dark muscle; the silver surface; the highest fat content and the lowest level of α-tocopherol. Concerning the fatty acid pattern in the three layers, the amount of C20: 5, C18:1 and C20:1 in the fat gradually decreased from the under skin layer towards the inner part of the fillet, whereas the opposite was true for C22: 6. © 1998 Society of Chemical Industry.     

The role of lipid oxidation on biscuit texture during storage

The role of lipid oxidation and humidity absorption on the shelf life of biscuits was analysed. Biscuits with low lipid and sugar content were prepared employing different oils, and texture changes that biscuits experience during storage were studied. Water activity, peroxide value, malonaldehyde content and colour were also determined at different storage times. The maximum peroxide level was between 1 and 1.5 mmol kg^?1 of oil, at 166 days of storage. Values of malonaldehyde were between 5.2 and 15.8 nmol g^?1 of dry sample. Water activity and peroxide value influence the biscuit texture (P ≤ 0.05). To study the effects of both factors simultaneously, a mathematical model was adjusted to the data. Results indicate that an increase in the peroxide level, even at low level of lipid oxidation, increases Young's modulus and leads to a harder biscuit, while the humidity absorption lowers the fracture stress and Young's modulus.     

Deterioration of European hake (Merluccius merluccius) during frozen storage

European hake (Merluccius merluccius (L)) was frozen as whole fish and as fillets and stored at ?18°C, ?24°C and ?30°C for up to 39 weeks. Sensory properties, peroxide value and thiobarbituric acid value, lipid fatty acid composition, adenosine nucleotide degradation products, dimethylamine and formaldehyde were measured at intervals during storage. Changes at ?30°C were negligible, otherwise fillets deteriorated faster than whole fish. Hedonic rating gave a storage life of around 9 months for whole fish stored at ?18°C.     

Influence of feeding state and frozen storage temperature on the lipid stability of Atlantic mackerel (Scomber scombrus)

Lipid deterioration of mackerel caught in Icelandic waters was studied, as affected by different frozen storage temperatures (?18 °C vs. ?25 °C) and seasonal variation (August vs. September). The lipid stability was investigated by analyses of hydroperoxide value (PV), thiobarbituric acid reactive substances (TBARS), free fatty acids, as well as changes in fatty acid composition. Results showed significant lipid deterioration with extended storage time, where the lower storage temperature showed significantly more protective effects. Furthermore, a higher lipid oxidation level was recorded for fish caught in September than in August, although lipid hydrolysis occurred to be greater for fish in August than in September. Moreover, results indicated a rather stable level of omega‐3 fatty acid during the whole frozen storage period. The analysis indicated that both lipid oxidation and hydrolysis were affected by the frozen storage temperature and the stability differed with regard to season of catch.     

Effects of plant extracts on lipid oxidation in fish croquette during frozen storage

The aim of this study was to investigate the effects of tomato and garlic extracts on lipid oxidation in fish croquette during frozen storage. The fish for croquette was purchased from the main fish market in Antalya, Turkey. Commercial tomato and garlic extracts were added into the croquette formulation. Lipid quality of frozen croquettes was analyzed at monthly intervals. There was no difference in free fatty acids and UV absorbance values of treatment groups. Treatment of tomato and garlic extracts kept oxidation at low levels. The results for thiobarbutiric acid, para-anisidine, and conjugated-diene values showed that tomato extract was the most effective in delaying lipid oxidation than garlic extract.     

Grape seed extract inhibits lipid oxidation in muscle from different species during refrigerated and frozen storage and oxidation catalyzed by peroxynitrite and iron/ascorbate in a pyrogallol red model system

The antioxidant effect of grape seed extract (GSE) was determined by assessing the bleaching of pyrogallol red (PGR) by peroxynitrite or iron/ascorbate, and the formation of lipid hydroperoxides (LOOH) and thiobarbituric acid substances (TBARS) in raw or cooked ground muscle during refrigerated or frozen storage. In PGR models, GSE was more effective than gallic acid in inhibiting oxidation. The formation of LOOH and TBARS was inhibited by GSE (0.1% and 1.0%) compared to untreated controls and samples treated with sodium tripolyphosphate. Diethylenetriaminepentaacetic acid (DTPA), alone or in combination with GSE, had no effect on LOOH or TBARS, which provides clues about the possible mechanism of action of GSE. These results show that GSE at concentrations as low as 0.1% is a very effective inhibitor of primary and secondary oxidation products in various muscle systems and has potential as a natural antioxidant in raw and cooked meat systems.     

Effects of freezing temperature and duration of frozen storage on lipid and protein oxidation in chicken meat

This study examined the effects of freezing temperature and duration of frozen storage on lipid and protein oxidation in chicken leg and breast meat. The meat was frozen at three different temperatures (−7, −12 and −18 °C) and then stored at −18 °C for up to 6 months. A significant effect of frozen storage duration on lipid oxidation was detected in leg and breast meat, whereas freezing temperature had no significant effect. In leg meat, freezing at −7 °C had a significant impact on protein oxidation, measured as the increase in carbonyl groups and the decrease in total sulphydryl groups, after 3 months of frozen storage. Lipid and protein oxidation appeared to occur simultaneously in chicken meat during frozen storage and was more intense in leg meat than in breast meat.     

Culinary herbs inhibit lipid oxidation in raw and cooked minced meat patties during storage

The effect of dried spices and the ethanol extract of those spices was studied on the stability of fresh chicken minced meat, and fresh and cooked pork patties pretreated with NaCl during refrigerated and frozen storage. The antioxidant activities of the spices were measured by thiobarbituric acid reactive substances (TBARS) and peroxide value (POV) in meat samples. The lipid oxidation was effectively inhibited in the chicken meat treated with several dry spices diminishing the TBARS to a range of 32% and 83% of those found in the control samples in frozen stored meat for 6 months. Marjoram, wild marjoram and caraway were the most effective dry spices. Ethanolic extracts of the same spices were more potent as antioxidants by lowering the concentration of the TBARS to a range of 20–27% of those found in the control samples. Addition of sodium salt to the minced pork resulted very high concentrations of the oxidation products originated from the polyunsaturated fatty acids. The treatment with ethanolic extract of spices (sage, basil, thyme and ginger) significantly inhibited the lipid peroxidation in refrigerated and chilled pork patties pretreated with NaCl by reducing both POV and TBARS. Heat treatment with microwaves produced significantly elevated levels of both lipid peroxides and TBARS, but the amount of these oxidation products was less than 10% in spice‐treated salted meat samples compared to that in untreated ones. Lipid peroxidation also grew continuously during the storage period at −18°C in raw and cooked samples. Ethanolic extracts of spices had a very strong antioxidative effect inhibiting lipid peroxidation in heat‐treated meat products during frozen storage. The highest antioxidant activity was observed in the case of ginger. High correlation coefficients were found between TBARS and POV both in raw and cooked pork patties (0.86, 0.91, respectively) during frozen storage. It is supposed that these compounds originated from the polyunsaturated fatty acids during oxidation processes but at different stages. Utilization of spices, spice mixtures or spice extracts in semi‐prepared meat products intended to be frozen for up to 6 months or more before consumption is proved to be advantageous in regard of shelf life of the food, as well as of human health, because of the beneficial effect of spices in inhibition of lipid peroxidation during heat treatment and chilling storage. © 1999 Society of Chemical Industry     

Foaming capacity of fish minces during frozen storage

This work covers a year's study of the foaming capacity (FC) of minced muscle of three fish species—blue whiting (Micromesistius poutassou R). horse mackerel (Trachurus trachurus L), and mackerel (Scomber scombrus L)—caught in two different seasons (January and July) and stored at – 18°C. Periodic assays were performed to determine protein solubility, FC and dimethylamine formation. The results show that FC is initially inhibited by the presence of the species own lipids; however, during frozen storage this effect is attenuated and thus FC increases. The results corroborate the view that protein solubility is not an indispensible requisite for FC, and that mere dispersion of proteins is sufficient. However, FC is not diminished by changes in protein during frozen storage when this deficiency is offset by sufficient protein concentration. On the other hand, FC is clearly affected by the formaldehyde generated during frozen storage, so that beyond a certain level the aggregates formed as a result of formaldehyde formation are too large to disperse, and hence FC decreases drastically.     

Green tea and grape seed extracts — Potential applications in food safety and quality

Using “natural green” plant extracts or their derived products in various food and beverage applications is an increasing trend in the food industry. Selection of these plant extracts and their application depends on their functional properties, availability, cost effectiveness, consumer awareness and their effect on the sensory attributes of the final product. Green tea extract (GTE) and grape seed extract (GSE) are two popular plant extracts that have been widely used in various food and beverage applications. Green tea is a widely consumed beverage that has attracted more attention in the recent years due to its health benefits like antioxidant, antimicrobial, anticarcinogenic and anti-inflammatory properties. Grape seed extract is derived from the grape seeds that is extracted, dried and purified to produce polyphenolic compounds-rich extract that also has well documented antioxidant, antimicrobial and anti-inflammatory properties. These two plant extracts (polyphenolic and proanthocyanidin rich compounds) have potential antioxidant properties by inhibiting the lipid oxidation and warmed over flavors and antimicrobial activities against major food borne pathogens like Listeria monocytogenes, Salmonella Typhimurium, Escherichia coli O157:H7, and Campylobacter jejuni in preventing pathogen contamination. Furthermore, they have demonstrated synergism in antimicrobial activity when used in combination with organic acids (malic, tartaric acid, benzoic acids etc.), bacteriocins like nisin or chelating agents like EDTA in various model systems including fresh produce (fruits and vegetables), raw and ready-to-eat meat and poultry products. Apart from beneficial effects of grape seed extract in food safety and quality, concerns regarding the side effects of GSE are also addressed. Nevertheless, persistent recalls of the food products involving foodborne pathogens despite various control measures calls for efficient bacteriostatic and bactericidal agents and technologies to deliver the active components for an effective inhibition of pathogens. Therefore, further research involving electrostatic spray and nanoscale delivery of the active components present in these natural, green, plant extracts and using them as a component in multiple hurdle approach would enhance the food safety and quality in addition to providing alternative “green” solutions to the food processors.     

Evaluation of the antioxidant potential of grape seed and bearberry extracts in raw and cooked pork

The effect of grape seed extract (GSE) and bearberry (BB), on lipid oxidation (TBARS, mg malondialdehyde (MDA)/kg muscle), colour (CIE ‘a’ redness value), pH, microbial status (log₁₀CFU colony forming units/g pork) and sensorial properties of cooked pork patties was investigated. GSE (0–1000 μg/g muscle) and BB (0–1000 μg/g muscle) were added to raw pork (M. longissimus dorsi) patties which were stored in modified atmosphere packs (MAP) (75% O₂:25% CO₂) for up to 12 days at 4 °C. Cooked pork patties were stored in MAP (70% N₂:30% CO₂) for up to 4 days at 4 °C. Mesophilic plate counts and pork pH were unaffected by GSE and BB. GSE and BB addition decreased (P < 0.05) lipid oxidation (TBARS) in raw pork patties on days 9 and 12 of storage, relative to controls. Antioxidant activity of GSE and BB was observed in cooked pork patties demonstrating the thermal stability of GSE and BB. The ‘a’ redness values of raw and cooked pork patties marginally increased with increasing GSE concentration. The sensory properties of cooked pork patties were unaffected by GSE and BB addition. Results obtained demonstrate the potential for using health promoting nutraceuticals in meat and meat products.     

The effects of brined onion extracts on lipid oxidation and sensory quality in refrigerated cooked turkey breast rolls during storage

The effects of brined onion extracts on selected aspects of quality in cooked encased turkey breast rolls were evaluated during refrigerated storage over 7 days. Using the thiobarbituric acid (TBA) assay, a 50% strength juice gave a significant reduction (P < 0.0001) in lipid oxidation in both 100 g and 1 kg rolls relative to controls. Quercetin, the main onion juice antioxidant, was reduced by 65% in freshly cooked 1 kg rolls compared with raw rolls but changed little thereafter in storage. Cook yields were significantly higher for rolls containing added onion extracts than for controls (P < 0.05) but no colour differences were detected using Hunter Lab values (P ? 0.05). A 30-member untrained sensory panel expressed no preference for freshly opened 4 day-stored control or onion extract-supplemented rolls packed in plastic casings but there was a significant preference (P < 0.05) for the onion extract product when 4 mm thick meat slices were stored in air for an additional 24 h.     

Wine industry residues extracts as natural antioxidants in raw and cooked chicken meat during frozen storage

The effect of Isabel (IGE) and Niagara (NGE) grape seed and peel extracts on lipid oxidation, instrumental colour, pH and sensory properties of raw and cooked processed chicken meat stored at -18°C for nine months was evaluated. The pH of raw and cooked samples was not affected by the addition of grape extracts. IGE and NGE were effective in inhibiting the lipid oxidation of raw and cooked chicken meat, with results comparable to synthetic antioxidants. The extracts caused alterations in colour, as evidenced by the instrumental (darkening and lower intensity of red and yellow colour) and sensory results of cooked samples. In the sensory evaluation of odour and flavour, IGE produced satisfactory results, which did not differ from synthetic antioxidants. These findings suggest that the IGE and NGE are effective in retarding lipid oxidation of raw and cooked chicken meat during frozen storage.     

葡萄籽提取物对葵花籽油抗氧化活性的研究

研究葡萄籽提取物对葵花籽油的抗氧化性能,实验证实葡萄籽提取物对油脂氧化有很好的抑制作用。在油脂中葡萄籽提取物的抗氧化性强于Vc、VE,预示其在粮油食品中具有广阔的应用前景。     

茶籽在贮藏过程中主要成分的变化

介绍了茶籽中主要成分在近6个月的贮藏过程中的变化情况。经过测定茶籽仁中的水分、蛋白质、脂肪、游离脂肪酸、淀粉和总糖的含量,得知在贮藏过程中茶籽仁中的水分和总糖的含量呈逐步下降的趋势,蛋白质含量呈波浪状缓慢下降,脂肪含量略有上升,淀粉的含量变化亦不大,而游离脂肪酸含量随贮藏时间的增加呈直线上升状态。实验表明,在11月至来年3月这一段时间内,在室温条件下贮藏干茶籽是一种经济有效的方法。     

Evaluation of lipid oxidation in horse mackerel patties covered with borage-containing film during frozen storage

Lipid oxidation of horse mackerel (Trachurus trachurus) patties covered with fish gelatin-based films containing a borage seed extract were evaluated, including commonly used analytical indexes (peroxide value, thiobarbituric acid reactive substances, polyene ratio), as well as determination of volatile compounds, quantitation of oxidized triacylglycerols and analysis by Fourier transform infrared (FTIR) spectroscopy, during 240 days of frozen storage and subsequent thawing and 4 days-chilling. Vacuum packaged-patties and control uncovered patties were also tested for comparative purposes. Methods applied to evaluate lipid oxidation in extracted lipids, i.e. peroxide value, quantitation of oxidized triacylglycerols and FTIR, clearly provided a better picture of the oxidation progress and led to similar conclusions. Film had protective effects on lipid oxidation of horse mackerel patties throughout frozen storage and particularly after thawing and chilled storage. Furthermore, when compared to vacuum packaging, film was found to be similarly effective until advanced stages of oxidation were reached and exerted enhanced protection once samples were thawed and exposed to air oxygen under chilling temperature; with the additional advantage of increasing the antioxidant capacity of muscle.