The effects of natural antioxidants and lighting conditions on the quality of salmon (Salmo salar) fillets packaged in modified atmosphere

The effect of lighting conditions (darkness, a low‐UV colour‐balanced lamp and supermarket fluorescents), along with the application of natural antioxidants (rosemary extract and ascorbic acid) on shelf‐life of salmon (Salmo salar) fillets packaged in modified atmosphere and stored at 1 ± 1 °C was studied. Darkness and lighting with low‐UV colour‐balanced lamps led to an extension of shelf‐life compared with conventional light, as assessed by a* values, lipid oxidation (TBARS value) and sensory evaluation. The application of natural antioxidants on the surface of MAP salmon fillets gave rise to a delay of lipid oxidation as well as an improvement of the sensory quality, mainly in the case of conventional lighting conditions. Copyright © 2005 Society of Chemical Industry     

Antioxidant Action of Borage, Rosemary, Oregano, and Ascorbic Acid in Beef Patties Packaged in Modified Atmosphere

ABSTRACT: Beef patties containing either ascorbic acid, rosemary, oregano, or borage were evaluated for storage stability at 2 ± 1 °C, by measuring a* and H* values, surface metmyoglobin, TBARS, psychrotrophic bacteria counts, and sensory off‐odor and discoloration. All of the antioxidants (except ascorbic acid) reduced (p < 0.01) TBARS formation, which was totally inhibited by borage. Myoglobin oxidation and color fading were inhibited (p < 0.01) by rosemary, oregano, and borage. Microbial growth showed insignificant differences among treatments. Sensory results showed that rosemary, oregano, and borage extended beef patties' shelf life from 8 to 12 d, while rosemary plus ascorbic acid extended shelf life an additional 4‐d period.     

Antioxidant effect of rosemary,borage, green tea,pu‐erh tea and ascorbic acid on fresh pork sausages packaged in a modified atmosphere: influence of the presence of sodium chloride

Fresh pork sausages formulated with and without salt, and with antioxidant mixtures containing either rosemary extract, green tea powder, pu‐erh tea infusion or borage meal and their mixtures with ascorbic acid, were packaged in an atmosphere containing four parts O₂ with one part CO₂ (v/v) and stored in the dark for 20 days. In a series of three experiments, the following parameters were measured at 4‐day intervals: instrumental colour (CIE L* and a*), thiobarbituric acid reactive substances (TBARS), aerobic psychrotroph counts and sensory off‐odour and discolouration. NaCl caused a decrease of the L* value and promoted lipid oxidation, but it protected sausages from discolouration. Green tea powder, pu‐erh tea infusion and borage meal caused a strong inhibition of lipid oxidation, dependent on the concentration used, but they failed to protect sausages from colour loss, even in the presence of ascorbic acid. Rosemary extract plus ascorbic acid strongly inhibited lipid oxidation and therefore off‐odour formation, delayed sausage discolouration and inhibited microbial growth, extending the shelf‐life of salted fresh pork sausages by at least 4 days. Copyright © 2006 Society of Chemical Industry     

Effects of rosemary and sage tea extracts on the sensory,chemical and microbiological changes of vacuum‐packed and refrigerated sardine (Sardina pilchardus) fillets

The effect of the natural antioxidants and antimicrobials from ethanol extracts of rosemary and sage tea on sensory, chemical [Total volatile basic nitrogen (TVB‐N), thiobarbituric acid reactive substances (TBARs), peroxide value (PV), free fatty acid (FFA)] and microbiological (total viable count‐TVC and total coliform count) changes of vacuum‐packaged sardine (Sardina pilchardus) fillets stored at 3 ± 1 °C was investigated for 20 days. The fish fillets were divided into three groups: untreated group (control, C) and treated groups that were immersed in a 1 L of distilled water containing 10 g rosemary (R group) or sage tea (S group) extracts for 4 min. The shelf life of sardine fillets was found to be 13 days for control (C), 20 days for R and S groups according to sensory assessment results, whose corresponded microbiological assessment showed a shorter shelf life (5 days for C group, 9 for R and S groups). At the end of storage period, TBARs values were 0.98 mg malonaldehyde kg^?1 for C group, 0.66 malonaldehyde kg^?1 for R group and 1.44 mg malonaldehyde kg^?1 for S group. Microbiological results showed that natural compounds from rosemary and sage tea resulted in a lower bacterial growth in fish fillets during the storage period.     

Influence of chitosan/clay functional bionanocomposite activated with rosemary essential oil on the shelf life of fresh silver carp

A combination of chitosan biopolymer, nanoclay and rosemary essential oil was prepared as a functional bionanocomposite (FBN). Its ability to improve the shelf life of refrigerated (4 ± 1 °C) silver carp fillets was studied. The fresh fillets were left untreated as a control or coated with chitosan, chitosan/clay bionanocomposite and chitosan/clay/rosemary essential oil (Ch/clay/REO) FBN. Then, they were evaluated for chemical, microbial and sensory properties over 16‐day storage. The samples coated with the FBN had the lowest pH and total volatile basic nitrogen. Ch/clay/REO coating efficiently retarded lipid oxidation by decreasing peroxide, free fatty acid and thiobarbituric acid production in the samples. The coating also reduced total viable and psychrotrophic count of the fillets more than 1.5 log by the end of storage.     

Shelf life of meat from lambs given essential oil-free rosemary extract containing carnosic acid plus carnosol at 200 or 400 mg kg

The use of dietary rosemary extract (DRE) at low doses is proposed as a nutritional strategy to improve meat preservation. Lamb diet was supplemented with 0, 200 or 400 mg DRE (containing carnosic acid and carnosol at 1:1 w:w) per kg feed during the fattening stage. Meat quality was evaluated in lamb fillets packed under protective atmosphere and kept in retail conditions for up to 14 days. The effects of diet and storage time were determined on different physical–chemical (L*a*b* color, pH, TBARS, protein oxidation and volatiles from lipid oxidation), microbial (total viable and psychrophilic bacteria, Enterobacteriaceae, molds and yeasts) and sensory (appearance and odor) characteristics of the meat. The antioxidant and antimicrobial effects of DRE on meat were demonstrated. DRE delayed lean and fat discoloration, lipid oxidation, odor deterioration and microbial spoilage, extending the shelf life time of fillets from around 9 to 13 days. Both DRE doses provided similar shelf life extension.     

Partial replacement of NaCl by KCl in salted mackerel (Scomber japonicus) fillet products: effect on sensory acceptance and lipid oxidation

Mackerel fillets were salted with NaCl and/or KCl to determine the most acceptable level by sensory evaluation. Additionally, the effects of ascorbic acid, vacuum packaging, and cold storages on lipid oxidation were determined for the salted mackerel fillets. Appropriate level of NaCl was ≤2%. Fifty percent replacement of NaCl by KCl reduced NaCl level with minimal impact on sensory quality. The higher the level of ascorbic acid (0–0.5%, weight basis), the higher the antioxidant effect observed with thiobarbituric acid value and peroxide value. There was no significant difference in sourness (α = 0.05) between the salted mackerel samples treated with and without ascorbic acid (0.25%). Vacuum packaging and storage at ?18 °C along with ascorbic acid was most effective in retarding lipid oxidation in the salted mackerel. Vacuum‐packaged sample with ascorbic acid stored at 2 °C was least oxidised, followed by vacuum packaging without ascorbic acid and then ascorbic acid without vacuum.     

The capability of rosemary extract in preventing oxidation of fish lipid

The effects of rosemary extract at different levels (%1, R1, and %2, R2) on the quality of vacuum‐packed sardine in terms of sensory, biochemical (thiobarbituric acid, total volatile basic nitrogen, peroxide value and free fatty acids) and microbiological analyses (total viable counts) were investigated. Fish were filleted and divided into three groups. First group was used as the control (C) without rosemary extract, second group was treated with 1% rosemary extracts (10 g L^?1) for 2 min (R1), and the third was treated with 2% rosemary extracts (20 g L^?1) for 2 min (R2). Thirty fillets per litre were used. After that, all groups were vacuum‐packed in polyethylene bags. The samples were stored in the refrigerator condition (4 ± 1 °C) over the storage period of 20 days. The results showed that the use of rosemary extract improved the sensory quality of both raw and cooked sardine, most preferably sardine treated with 1% of rosemary. Biochemical analysis showed that the use of 2% of rosemary extract were found to be most effective (P < 0.05) in controlling the rate of lipid oxidation.     

Effect of anchovy by-product protein coating incorporated with thyme essential oil on the shelf life of anchovy (<Emphasis Type="Italic">Engraulis encrasicolus</Emphasis> L.) fillets

The effects of anchovy by-product protein coatings incorporated with thyme essential oil (TEO) on the shelf life of anchovy (Engraulis encrasicolus L.) fillets stored at 4 ± 1 °C were investigated. We grouped fillets in three categories: untreated fillets, fillets treated in coating solution alone, and fillets treated in coating solution containing 1.5% TEO and analyzed on 0, 3, 6, and 9 days of storage. It was observed that the total volatile basic nitrogen (TVB-N) and pH of all the fillet groups increased under cold storage conditions; however, this increase was much slow in both the coated anchovy fillets. Both coating applications slowed down the lipid oxidation but the coating containing TEO exhibited better effect than coating alone. The coating application alone or with essential oil had limited effect on microbial growth but positively affected the sensory quality. These results revealed that anchovy by-product protein coating mixed with TEO may prolong anchovy fillets’ shelf life stored under cold condition.     

Development of lipid oxidation and flesh colour in frozen stored fillets of Norwegian spring-spawning herring (Clupea harengus L.). Effects of treatment with ascorbic acid

Frozen stored fillets from Norwegian spring spawning herring (Clupea harengus L.) become discoloured. Based on the hypothesis that lipid oxidation in the fillets caused discoloration, we designed an experiment where ascorbic acid was added to the water (2 g l⁻¹) in RSW-tanks on board a fishing vessel and/or by spray (20 g l⁻¹) after filleting but before freezing. Treatment with ascorbic acid on board and on the fillet line led to 8- and 17–24-fold increases, respectively, in the ascorbic acid concentration in the herring fillets. Ascorbic acid treatment on the fillet line, but not the treatment on board, protected the herring fillets against oxidation during freezing, an effect that could be detected until 9 weeks of storage at −30 °C. Between 9 and 14 weeks of storage there was a new burst of lipid oxidation where the treatments had no effect. There was a large variation in colour within each fillet and between fillets in the same group. During freezing, the amount of yellow colour increased substantially and the amount of red colour increased in the posterior end of the fillets, causing a visible change in appearance. Thereafter only minor changes occurred until week 10 but, in week 30, the fillets had become less red, causing a less fresh and more grey appearance. Compared to the within fillet and within group variations, there were only minor effects of ascorbic acid treatment on colour. It is suggested that shelf life of frozen herring fillets should be set at between 9 and 14 weeks at −30 °C. Treatment with ascorbic acid will not alleviate the discoloration of frozen herring fillets.     

Effects in ewe diet of rosemary by-product on lipid oxidation and the eating quality of cooked lamb under retail display conditions

Distilled dietary rosemary leaf (DRL) was tested to prevent lipid oxidation and sensory deterioration of cooked lamb under retail display conditions. Pregnant sheep were fed with a basal diet supplemented by 0%, 10% and 20% DRL. Cooked lamb fillets were stored for 0, 2 or 4 days at a temperature of 4 °C in a display cabinet and re-heated, simulating catering practices. The cooked lamb suffered rapid lipid oxidation and odour and flavour spoilage associated with slight rancidity and warmed-over flavour, and, to a lesser extent, with loss of colour and juiciness. DRL feeding delayed lipid oxidation measured as TBARS and volatile compounds, this being more effective in the first two days of storage. 10% and 20% of DRL provided equal antioxidant capacity. However, DRL feeding hardly prevented sensory deterioration, although incipient rancidity was delayed. Feeding DRL to ewes contributed to extend the shelf life of cooked lamb under retail display conditions.     

香辛料提取物对低温油炸肉丝软罐头的抗氧化效应研究

目的通过添加具有抗氧化活性和较高安全性的香辛料提取物,解决中式肉类菜肴的软罐头食品中变色、风味变差以及脂肪氧化酸败等问题。方法向低温油炸肉丝软罐头中添加不同添加量的迷迭香、肉桂和VE提取物以及2种人工合成抗氧化剂丁基羟基茴香醚(butyl hydroxy anisd,BHA)和没食子酸丙酯(propylgallate,PG),测定其对软罐头菜肴产品在贮藏过程中硫代巴比妥酸值(thiobarbituric acid-reacitive substances,TBARS值)、过氧化物值(peroxide value,POV值)和色差值的影响。结果添加的3种共9组天然抗氧化剂中,迷迭香提取物抑制初级氧化产物氢过氧化物和次级氧化产物丙二醛的效果最好(P0.05)。添加300 mg/kg迷迭香、90 mg/kg PG和120 mg/kg BHA的3组处理组在21 d冷藏期内,其POV值和TBARS值显著小于其他各组(P0.05),说明添加300 mg/kg迷迭香可以替代人工抗氧化剂。结论低温油炸肉丝软罐头中添加300 mg/kg迷迭香提取物,可以减缓脂肪氧化速度,进而延长产品的货架期。     

Evaluation of different natural antioxidants as affecting volatile lipid oxidation products related to off-flavours in corn flakes

Different types of natural antioxidants (tocopherols – alone, in two different doses, or combined with ascorbic acid – and a rosemary extract) were employed in the production of corn flakes, to select the most effective ones for achieving low levels of volatile lipid oxidation products, related to off-flavours, after long-term storage. Samples were submitted to SPME/GC/MS and sensory analyses. Multivariate analysis elucidated the contribution of the volatile compounds to the sensory properties of corn flakes. Under the experimental conditions, tocopherols conferred better antioxidant activity than did rosemary extract, leading to low levels of off-flavour compounds, with a further improvement provided by the synergistic activity of ascorbic acid. This could be attributed to interfacial and phase partitioning phenomena involving antioxidants, depending on their lipo- or hydrophilicity, in heterogeneous food products. Acids, n-alkanols, lactones and some aldehydes appeared to have a considerable influence on the intensity of the off-flavours.     

Effects of Ultraviolet Light (UV‐C) and Heat Treatment on the Quality of Fresh‐Cut Chokanan Mango and Josephine Pineapple

The effects of ultraviolet (UV‐C) and medium heat (70 °C) treatments on the quality of fresh‐cut Chokanan mango and Josephine pineapple were investigated. Quality attributes included physicochemical properties (pH, titratable acidity, and total soluble solids), ascorbic acid content (vitamin C), antioxidant activity, as well as microbial inactivation. Consumers’ acceptance was also investigated through sensory evaluation of the attributes (appearance, texture, aroma and taste). Furthermore, shelf‐life study of samples stored at 4 ± 1 °C was conducted for 15 d. The fresh‐cut fruits were exposed to UV‐C for 0, 15, 30, and 60 min while heat treatments were carried out at 70 °C for 0, 5, 10 and 20 min. Both UV‐C and medium heat treatments resulted in no significant changes to the physicochemical attributes of both fruits. The ascorbic acid content of UV‐C treated fruits was unaffected; however, medium heat treatment resulted in deterioration of ascorbic acids in both fruits. The antioxidants were enhanced with UV‐C treatment which could prove invaluable to consumers. Heat treatments on the other hand resulted in decreased antioxidant activities. Microbial count in both fruits was significantly reduced by both treatments. The shelf life of the fresh‐cut fruits were also successfully extended to a maximum of 15 d following treatments. As for consumers’ acceptance, UV‐C treated fruits were the most accepted as compared to their heat‐treated counterparts. The results obtained through this study support the use of UV‐C treatment for better retention of quality, effective microbial inactivation and enhancement of health promoting compounds for the benefit of consumers.     

The Effect of Buckwheat Hull Extract on Lipid Oxidation in Frozen‐Stored Meat Products

This study investigated the effect of antioxidants on lipid stability of frozen‐stored meat products. Buckwheat hull extract was used to enrich fried meatballs made from ground pork. During 180‐d storage of meat products, lipid oxidation (peroxide and 2‐thiobarbituric acid reactive substances [TBARS] value) was periodically monitored. The results were compared with butylated hydroxytoluene (BHT). The addition of antioxidants decreased lipid oxidation in stored meatballs. The highest ability to control peroxide and TBARS values was demonstrated for buckwheat hull extract. Moreover, buckwheat hull extract showed a higher 2,2‐diphenyl‐1‐picrylhydrazyl free radical scavenging activity as well as higher Fe(II) ion chelating ability, as compared with BHT. The total content of phenolic compounds are highly correlated to the individual polyphenols in extract of buckwheat hull, among which the following were assayed: 3,4‐dihydroxybenzoic acid, 4‐hydroxybenzoic acid, gallic acid, isovanillic acid and p‐coumaric acid, and flavonoids: isoorientin, quercetin, quercetin 3‐d ‐glucoside, rutin, and vitexin. These results indicate that plant extracts can be used to prolong shelf life of products by protecting them against lipid oxidation and deterioration of their nutritional quality.     

The effects of ascorbic acid, taurine, carnosine and rosemary powder on colour and lipid stability of beef patties packaged in modified atmosphere

This research was aimed at evaluating the inhibition of oxidative changes of beef patties packaged in modified atmosphere (70% O₂+20% CO₂+10% N₂) by natural antioxidants: ascorbic acid (500 ppm), taurine (50 mM), carnosine (50 mM), rosemary powder (1000 ppm) and their combinations with the first. Beef patties stored at 2±1°C for 20 days were evaluated for colour (L*, a*, b*, C* and H*), TBARS, metmyoglobin formation (% of total myoglobin), psychrotrophic microbial counts and sensory odour and discolouration. Rosemary, either alone or with ascorbic acid, was highly effective in inhibiting both metmyoglobin formation and lipid oxidation; sensory analysis was in agreement with these results. Ascorbic acid, ascorbic acid+taurine and ascorbic acid+carnosine treatments showed a limited inhibitory effect of myoglobin oxidation, while carnosine and carnosine+ascorbic acid were effective in inhibiting lipid oxidation. Taurine alone failed to exert any antioxidant effect. Principal components analysis confirmed these results.     

Modeling Microbial Spoilage and Quality of Gilthead Seabream Fillets: Combined Effect of Osmotic Pretreatment,Modified Atmosphere Packaging,and Nisin on Shelf Life

ABSTRACT: The objective of the study was the kinetic modeling of the effect of storage temperature on the quality and shelf life of chilled fish, modified atmosphere-packed (MAP), and osmotically pretreated with the addition of nisin as antimicrobial agent. Fresh gilthead seabream (Sparus aurata) fillets were osmotically treated with 50% high dextrose equivalent maltodextrin (DE 47) plus 5% NaCl. Water loss, solid gain, salt content, and water activity were monitored throughout treatment and treatment conditions were selected for the shelf life study. Untreated and osmotically pretreated slices with and without nisin (2 × 10⁴ IU/100 g osmotic solution), packed in air or modified atmosphere (50% CO₂–50% air), and stored at controlled isothermal conditions (0, 5, 10, and 15 °C) were studied. Quality assessment and modeling were based on growth of several microbial indices, total volatile nitrogen, trimethylamine nitrogen, lipid oxidation (TBARS), and sensory scoring. Temperature dependence of quality loss rates was modeled by the Arrhenius equation, validated under dynamic conditions. Pretreated samples showed improved quality stability during subsequent refrigerated storage, in terms of microbial growth, chemical changes, and organoleptic degradation. Osmotic pretreatment with the addition of nisin in combination with MAP was the most effective treatment resulting in significant shelf life extension of gilthead seabream fillets (48 days compared to 10 days for the control at 0 °C).     

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.     

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.     

Rheological and differential scanning calorimetry studies on structural and textural changes in frozen Atlantic mackerel (Scomber scombrus)

The viscoelastic behaviour and thermal stability of Atlantic mackerel fillets stored at ?20 and ?30 °C for up to 2 years were investigated. An increase in elastic (G′) and viscous (G″) modulus values, reflecting protein aggregation, was observed in samples stored at ?20 °C compared with those stored at ?30 °C, as well as with storage time. The results indicate that toughening on frozen storage is not just limited to lean gadoid fish but also occurs in fatty fish, leading to texture deterioration. Differential scanning calorimetry of fillets stored at ?20 °C showed a shift to a lower transition temperature (T_m) and a decrease in enthalpy (ΔH) compared with control fillets stored at ?30 °C; this change was enhanced when fillets were stored for a longer period of time, confirming protein denaturation and the formation of aggregates reported previously by the authors (J Sci Food Agric 82: 579–586 (2002)). The contribution of lipid oxidation to protein aggregation was shown by storing minced mackerel with or without the antioxidant vitamin E at ?10 °C. The G′ and G″ values were higher in samples stored without vitamin E than in samples stored with vitamin E; thus antioxidants may be used to minimise protein aggregation in fatty fish. The role of lipid oxidation in promoting protein aggregation and deterioration in the texture of fatty fish has not been reported hitherto. Antioxidants such as vitamin E may be used not only to prevent lipid oxidation but also to minimise protein damage in order to prolong the shelf‐life of fatty fish. Copyright © 2004 Society of Chemical Industry