Capability of the rosemary (Rosmarinus officinalis) extract on the oxidative stability of cooked sea bream (Sparus aurata) during frozen storage

The effects of rosemary extract addition on oxidative stability of cooked sea bream during frozen storage period were investigated. Sea bream fillets were fried, oven baked and grilled. Three groups with rosemary extract were also cooked by the same methods and cooked samples (with and without rosemary extract) were stored in ?18?°C for 4?months. After cooking procedures, the FFA formation was quite similar in fresh-raw and fried sea bream fillets, but significantly increased oven baked (0.31?C0.33% oleic acid) and grilled fillets (0.39?C0.40% oleic acid). The highest value of PV was also obtained from grilled fillets (1.18?C1.58?meq/kg). However, TBA values (1.92?mg MA/kg for fresh-raw fillet) did not increase in sea bream fillets after the frying and grilling procedure except oven baking without rosemary extract (2.41?mg MA/kg). A considerable increase in the FFA, PV and TBA was observed in all cooked groups during frozen storage period. The treated samples with rosemary extract generally showed slower PV and TBA formation than those of the untreated samples. However, the additions of rosemary extract have positive effect on sensory quality of baked sea bream.     

Capability of the rosemary (Rosmarinus officinalis) extract on the oxidative stability of cooked sea bream (Sparus aurata) during frozen storage

The effects of rosemary extract addition on oxidative stability of cooked sea bream during frozen storage period were investigated. Sea bream fillets were fried, oven baked and grilled. Three groups with rosemary extract were also cooked by the same methods and cooked samples (with and without rosemary extract) were stored in −18 °C for 4 months. After cooking procedures, the FFA formation was quite similar in fresh-raw and fried sea bream fillets, but significantly increased oven baked (0.31–0.33% oleic acid) and grilled fillets (0.39–0.40% oleic acid). The highest value of PV was also obtained from grilled fillets (1.18–1.58 meq/kg). However, TBA values (1.92 mg MA/kg for fresh-raw fillet) did not increase in sea bream fillets after the frying and grilling procedure except oven baking without rosemary extract (2.41 mg MA/kg). A considerable increase in the FFA, PV and TBA was observed in all cooked groups during frozen storage period. The treated samples with rosemary extract generally showed slower PV and TBA formation than those of the untreated samples. However, the additions of rosemary extract have positive effect on sensory quality of baked sea bream.     

迷迭香活性包装对虾仁冷藏过程中脂质氧化与 质构的影响

目的研究不同浓度迷迭香活性包装对虾仁冷藏过程中脂质氧化与质构的影响。方法将不同浓度的迷迭香加入包装材料来保藏虾仁,研究冷藏过程中虾仁过氧化值(peroxide value,POV)、硫代巴比妥酸(thiobarbituric acid reactive substance,TBARS)值、巯基(sulfhydryl,SH)、Ca~(2+)-ATPase活性和质构特性的变化。结果迷迭香活性包装对冷藏期间虾仁的脂质氧化有一定的抑制作用,而且和迷迭香的浓度呈正相关。在虾仁冷藏的12天内,迷迭香添加量为0.75 mg/cm~2实验组的过氧化值相对于空白对照组降低47%,TBARS相对于空白对照组降低31%。质构数据表明,迷迭香活性包装能延缓虾仁硬度、弹性、咀嚼性的改变。结论迷迭香活性包装能有效抑制冷藏虾仁的品质变化,并能延缓质构劣变,是一种有潜力的虾仁包装技术。     

Inhibition of oxidative rancidity in frozen cooked fish flakes by tert-butylhydroquinone and rosemary extract

The antioxidant properties of tert-butylhydroquinone (0·5 g kg^?1 + 20 g kg^?1 ascorbic acid—TBHQ-AS) and an extract of rosemary (2·5 g kg^?1) alone and in combination were determined by their addition as solutions to cooked fish flakes stored at - 20°C. Oxidation was measured by following changes in free fatty acids, thiobarbituric acid number, fatty acid composition and sensory evaluation. The order of effectiveness in inhibiting oxidation was TBHQ-AS > combination > rosemary > untreated control ?70°C > untreated control -20°C. Sensory evaluation indicated that green aroma and flavor notes were associated with the rosemary extract, while fish oil notes were associated with untreated samples.     

充氮包装对全脂羊奶粉贮藏期间脂肪氧化稳定性的影响

采用加速氧化的方法研究充氮包装对全脂羊奶粉贮藏期间脂肪氧化稳定性的影响。通过测定全脂羊奶粉的酸值、过氧化值、硫代巴比妥酸值(TBA)、色度值等指标评价全脂羊奶粉贮藏期间脂肪的分解氧化状况。结果表明:充氮包装的全脂羊奶粉贮藏期间酸值、TBA值和色度值变化趋势较慢,分别于第6周后、第3周后、第7周后显著低于普通包装的全脂羊奶粉(p<0.05);充氮包装的全脂羊奶粉的过氧化值于第7周达到最高值13.54mmol/kg脂肪,变化速率显著小于普通包装的全脂羊奶粉(p<0.01)。说明充氮包装可延缓酸值、过氧化值、TBA值和色度值的变化速率,显著提高全脂羊奶粉脂肪的氧化稳定性。      

Effect of gelatin dip on the oxidative and colour stability of cooked ham and bacon pieces during frozen storage

Summary Samples of cooked ham and bacon were dipped in water or 2, 4 or 6% gelatin solutions. Samples were then packed in oxygen permeable or vacuum packaging film and stored at −18 °C for seven months. Lipid oxidation (TBARS) and colour stability (Hunter a* values) were assessed monthly. The gelatin coating exerted beneficial effects on oxidative and colour stability.     

迷迭香、茶多酚、VE对干腌火腿贮藏过程中抗脂质氧化及护色效果的研究

采用迷迭香、茶多酚、VE及其复合剂为抗氧化剂,喷淋于干腌火腿切块表面,研究其对切块火腿脂质抗氧化和护色的效果.结果表明:各处理组与空白对照差异显著(P<0.05).4个月后单一组茶多酚(T)、迷迭香(R)、VE(V)的过氧化值(POV)分别比空白对照降低了21%、51%、23%,TBARs值降低了12%、57%、36%;茶多酚+迷迭香(TR)、茶多酚+VE(TV)、迷迭香+VE(RV)的POV值分别降低了40%、39%、30%,TBARs值降低了46%、57%、48%.单一组中迷迭香抗氧化效果最佳(P<0.05),复合剂的相乘效用使其比单一组表现出更好的抗氧化效果(P<0.05),与BHT的效果相当.茶多酚(T)、迷迭香(R)、茶多酚+VE(TV)的护色效果显著(P<0.05).     

Improving the oxidative stability of sunflower seed kernels by edible biopolymeric coatings loaded with rosemary extract

An optimized combination of whey protein concentrate (WPC), glycerol and carboxymethyl cellulose (CMC) was determined by evaluating the mechanical properties of edible films and coating percentage on sunflower seed kernels (SUKs). The optimal coating solutions with/without rosemary extract (RAE) were used to improve oxidative stability of SUKs. Moreover, the efficiency of the coated SUKs was assessed in a sesame-based product, as a food system. The optimized composite coating (CMC 0.6% and WPC 8% by total solution weight, and glycerol 51% by WPC weight) provided the better color features for SUKs stored at elevated temperature compared to WPC coatings (10 and 11%, w/w) with a Maillard-induced red color, and it was more effective than CMC (4%, w/w) coating to improve the oxidative stability of the nuts. The RAE had a positive effect on the color characteristics of the composite and CMC coatings; however, it enhanced the oxidation of SUKs, which could be due to disruption of coating polymer network, and thus increasing the oxygen diffusion into the product. The food system containing the coated nuts exhibited a lower oxidation extent in comparison to the control formulation prepared by uncoated ones. Therefore, using an optimal composite coating, reddening of WPC at high temperatures and less oxidation protection efficiency of CMC were resolved as the kernels with desirable color and oxidative stability properties were produced, applicable in the formulation of products needing thermal processing.     

Antioxidant effects of broccoli powder extract in goat meat nuggets

The antioxidant potential of broccoli powder extract (BPE) was determined and evaluated in goat meat nuggets at three different levels 1, 1.5 and 2%, compared with control and butylated hydroxyl toluene (100ppm BHT). Total phenolics in 5mg broccoli powder was higher (P<0.05) than 100ppm BHT. Free radical scavenging activity of 2.25mg and 3mg broccoli powder was found similar to 50 and 100ppm BHT. Reducing power of 10mg broccoli powder was comparable to the 100ppm BHT. Incorporation of 1.5 and 2% BPE decreased (P<0.05) the pH value of the products. Total phenolics in product with 2% BPE was similar to BHT nuggets. Chroma value of products with 1.5 and 2% BPE was lower (P<0.05) than control and BHT nuggets. Thiobarbituric acid reactive substances number of BPE nuggets was lower (P<0.05) than control throughout the storage. Thus 2% BPE can be used as natural antioxidant in goat meat nuggets without affecting product acceptability.     

Effectiveness of a natural Rosemary (Rosmarinus officinalis) extract on the stability of filleted and minced fish during frozen storage

 The objective of this study was to evaluate the effect of adding a natural Rosemary (Rosmarinus officinalis L.) extract to filleted and minced frozen fish and to compare the fat stability of the samples with that of the controls. Horse mackerel (Trachurus trachurus), a relatively fatty fish, and Mediterranean hake (Merluccius mediterraneus), a low-fat fish, were used. Fat stability evaluation was done by comparing the changes of the malondialdehyde (MDA) content and the percentage of polyunsaturated fatty acid (PUFAs) degradation that occurred during frozen storage at –18°C for 120 days. Total volatile bases-N (TVB-N) were also measured to assess for quality. The results showed that the natural antioxidant extract retarded the oxidation process throughout storage. The control samples of both filleted and minced frozen fish of both species showed a significant reduction (^* P <0.05) of PUFAs until day 50 of storage, while the oxidation was gradual but slower in the treated samples. Fillets and minced samples of both species treated with antioxidant contained significantly (^* P <0.05) less MDA compared with the controls during storage. Received: 2 December 1996     

Effectiveness of a natural Rosemary (Rosmarinus officinalis) extract on the stability of filleted and minced fish during frozen storage

 The objective of this study was to evaluate the effect of adding a natural Rosemary (Rosmarinus officinalis L.) extract to filleted and minced frozen fish and to compare the fat stability of the samples with that of the controls. Horse mackerel (Trachurus trachurus), a relatively fatty fish, and Mediterranean hake (Merluccius mediterraneus), a low-fat fish, were used. Fat stability evaluation was done by comparing the changes of the malondialdehyde (MDA) content and the percentage of polyunsaturated fatty acid (PUFAs) degradation that occurred during frozen storage at –18°C for 120 days. Total volatile bases-N (TVB-N) were also measured to assess for quality. The results showed that the natural antioxidant extract retarded the oxidation process throughout storage. The control samples of both filleted and minced frozen fish of both species showed a significant reduction (^* P <0.05) of PUFAs until day 50 of storage, while the oxidation was gradual but slower in the treated samples. Fillets and minced samples of both species treated with antioxidant contained significantly (^* P <0.05) less MDA compared with the controls during storage. Received: 2 December 1996     

Antioxidant effects on retinyl palmitate stability and isomerization in nonfat dry milk during thermally accelerated storage

The effects of antioxidants on vitamin A oxidation and isomerization in nonfat dry milk (NFDM) were evaluated during thermally accelerated storage. High performance liquid chromatography was used to measure all-trans, 13-cis, 9-cis, and 9, 13-di-cis retinol present in two lots of antioxidant-treated, vitamin A and D fortified NFDM samples at zero, one, and two weeks of 50 °C storage. After two weeks, the NFDM sample retaining the most vitamin A was the one treated with butylated hydroxytoluene at 0.29 ppm with 250 ppm ascorbic acid; this treatment retained approximately 76% of its original retinol activity equivalents. The control retained significantly less than this: only 19% of its original vitamin A activity. Butylated hydroxytoluene in combination with ascorbic acid appears to be effective in the preservation of vitamin A in NFDM during heated storage; however, its use in dried beverage mixes is currently prohibited.     

Pigment and colour stability of frozen kiwi-fruit slices during prolonged storage

Changes in major pigment constituents of frozen kiwi-fruit slices during prolonged storage at –18° C and correlation with colour measurements (Hunter Lab parameters) were studied. Kiwi-fruit cultivars (Hayward, Bruno, Monty and Abbot) were processed without previous treatment and vacuum packed after freezing. HPLC using a diode array detector was used to individually quantify and identify the three major pigment components (xanthophylls, chlorophylls and derivatives and-carotene). The colour of fresh and frozen slices by Hunter Color values were correlated with each class of pigment compounds. An apparent first order degradation rate was found for total chlorophylls and xanthophylls. Hayward and Bruno were more suitable for prolonged freezing preservation in terms of colour deterioration.

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Haltbarkeit von Pigment und Farbe gefrorener Kiwifrucht-Scheiben während langer Lagerung

Zusammenfassung Es wurden die Veränderungen der meisten Pigmentbestandteile gefrorener Kiwifrucht-Scheiben während langer Lagerzeit bei –18°C und die Korrelation mit Farbmessungen studiert. Kiwifrüchte der Sorten Hayward, Bruno, Monty und Abbot wurden ohne vorherige Behandlung unter Vakuum direkt nach dem Gefrierprozeß verpackt. Mit HPLC wurde quantitativ gemessen und die drei Pigmentbestandteile Xanthophyll, Chlorophyll und-Carotin identifiziert. Die Farbe der frischen, gefrorenen Scheiben (Hunter-Farb-Werte) korrelierte mit jedem der Pigmentbestandteile. Ein Verlust, scheinbar erster Ordnung, wurde für Chlorophyll und Xantophyll bei den Sorten Hayward und Bruno beobachtet, jedoch sind sie für das Gefrieren bei langer Lagerzeit trotz Farbverlust geeignet.

     

Antioxidant protection of white grape pomace on restructured fish products during frozen storage

White grape antioxidant dietary fibre (WGDF) was obtained from white grape (Vitis vinifera, var. Airén) pomace from wine production. The antioxidant capacity of WGDF was determined in minced fish muscle (MFM) during frozen storage. Concentrations of 0, 2, and 4% WGDF ((0-WGDF), (2-WGDF), and (4-WGDF) respectively) were added to MFM samples. Analyses were carried out immediately after preparation of samples and over 6 months of storage at −20 °C. WGDF was characterized in terms of dietary fibre (DF) (insoluble and soluble), total polyphenols and antioxidant capacity, and multifunctional antioxidant assays were done on all the MFM samples. The addition of white grape DF considerably delayed lipid oxidation in minced horse mackerel muscle during the frozen storage. Vacuum-packing the sample with 2% WGDF significantly enhanced the antioxidant properties of WGDF.     

食品酶制剂改善冷冻面团贮藏稳定性的研究

应用F3发酵流变仪、质构仪研究了葡萄糖氧化酶和谷氨酰胺转胺酶对冷冻面团贮藏稳定性的影响.空白面团含有葡萄糖氧化酶面团和含有谷氨酰胺转胺酶面团于-18℃冷冻贮藏7,21,35 d,研究发现：三种面团经冷冻贮藏发酵高度均有所降低,产气能力下降;葡萄糖氧化酶和谷氨酰胺转胺酶抑制了冷冻贮藏对面团发酵高度、产气和持气能力的破坏.葡萄糖氧化酶和谷氨酰胺转胺酶稳定了面团流变学特性的变化.添加葡萄糖氧化酶和谷氨酰胺转胺酶冷冻面团面包比容增加、硬度减小;面包瓤更柔软、光滑、富有弹性,面包感官评分高.     

Effect of dietary vitamin E, fishmeal and wood and liquid smoke on the oxidative stability of bacon during 16 weeks' frozen storage

Twelve (Large White×Landrace) gilts were randomly allotted in a 2×2 factorial design with the respective factor being dietary vitamin E (10 or 200 mg/kg feed) and dietary fishmeal (0 or 5%). Bacon was manufactured from the meat obtained from the animals after slaughter using wood smoke only or a combination of liquid and wood smoke. The oxidative stability of the bacon was examined over 16 weeks of frozen storage. Lipid oxidation in the product was measured by means of thiobarbituric acid reactive substances (TBARS) and fluorescence shift. Dietary fishmeal supplementation increased lipid oxidation in bacon, while dietary vitamin E supplementation reduced lipid oxidation in the product. Lipid oxidation in frozen bacon was successfully reduced when bacon was manufactured from pigs fed a diet supplemented with or without 200 mg of α-tocopherol per kilogram of feed and processed with a combination of liquid and wood smoke. It is concluded that bacon processed with a combination of liquid and wood smoke was significantly less (P<0.001) susceptible to lipid oxidation than bacon processed with wood smoke only.