辣椒籽油对肉糜低温贮藏特性的影响

为探讨辣椒籽油对猪肉肉糜的保鲜效果,研究了辣椒籽油添加及不同包装方式对猪肉肉糜在4℃低温贮藏条件下的质构、色差、保水性、挥发性盐基氮、TBARS值、菌落总数等指标的影响。结果表明:辣椒籽油的添加使肉糜的红度值提高了2倍,且对肉糜的pH、硬度都有积极影响,辣椒籽油与真空包装结合使用使肉糜的脂肪氧化、蛋白氧化变缓。贮藏第9天对照组TBARS值已达到1.95mg/kg,辣椒籽油组仅1.39mg/kg;对照组TVB-N值达到28.7 mg/100g,辣椒籽油组仅16.8mg/100g。在辣椒籽油和真空包装的联合作用下可有效延长肉糜保质期2d以上。     

贮藏温度对不同脂肪含量牛肉糜品质及水分变迁的影响

为探索贮藏温度对不同脂肪含量牛肉糜品质及水分变迁的影响,本试验将牛脂肪添加量不同的牛肉糜(添加0%、10%、20%牛脂肪)托盘包装,分别在低温(2℃)和冰温(-1.5℃)条件下贮藏,于贮藏第0 d、3 d、6 d、9 d和12 d天测定其微生物和理化指标。试验结果表明,冷藏6 d时,添加20%牛脂肪组菌落总数及嗜冷菌数均超过6.00 log(cfu/g),为各处理组中最高值。贮藏第12 d时,三组冰温组的TVB-N值均低于国标规定的25 mg/100 g最高限值,而此时冷藏组(25.34～25.81 mg/100 g)已超过该限值。脂肪添加量对TBARS值影响显著,TBARS值增加速率从高到低变化顺序依次为:牛脂肪添加量20%10%0%。利用LF-NMR(low-field nuclear magneticresonance,LF-NMR)检测水分存在状态及迁移规律,发现冰温贮藏组T_(22)水分变化较小,T_(23)水分的自由度增大,不易流动水含量(P_(22))降低,自由水含量(P_(23))先增加后减少,温度对水分变迁影响显著。试验结果表明贮藏温度影响牛肉糜的理化品质及水分变迁,冰温贮藏可抑制微生物生长,提高产品的理化性质及水分存在状态的稳定性,同时牛脂肪添加对牛肉糜微生物性质及水分迁移影响不显著,但是会加剧脂质氧化,导致牛肉糜L*值和b*值增大,a*值降低。本研究为牛肉饼的原料配比及其贮藏方式提供理论指导和科学依据。     

刺梨水提物对牦牛肉糜贮藏过程蛋白质和脂质氧化影响的研究

本研究旨在探讨刺梨水提物（Rosa roxburghii Tratt Aqueous Extract,RRTAE）对牦牛肉糜在贮藏过程蛋白质和脂质氧化的影响规律。与空白对照、0.02%二丁基羟基甲苯（Butylated Hydroxy Toluene,BHT）进行比较,添加0.02%、0.10%、0.20% RRTAE到牦牛肉糜中,测定贮藏1、3、6、9 d各组牦牛肉糜的色泽、pH、硫代巴比妥酸（Thiobarbituric Acid Reactive Substances,TBARS）值、荧光化合物（有机相δ For、水相δ Faq）、共轭二烯（Conjugated Diolefins,CD）值、羰基含量、表面疏水性、色氨酸含量、二聚酪氨酸含量、感官品质。结果表明,与空白对照、阳性对照（0.02%BHT）相比,0.10%、0.20%RRTAE可显著降低牦牛肉糜的pH（P<0.05）,0.02%RRTAE与阳性对照组效果接近,且RRTAE可改善其感官品质,显著抑制a*、b*值的降低（P<0.05）,但对L*值有一定的负面作用;0.02% RRTAE可显著降低其TBARS值、二聚酪氨酸含量（P<0.05）,且抑制效果随RRTAE添加量的增加而提高;添加0.20% RRTAE可显著降低其δ Faq、羰基含量、表面疏水性、色氨酸荧光值（P<0.05）。本研究认为,RRTAE具有改善牦牛肉糜贮藏过程理化特性的作用,可以作为肉糜保鲜中有潜力的抗氧化剂。     

黄花菜粉对牛肉糜凝胶特性和流变性质的影响

该文研究黄花菜粉对牛肉糜凝胶特性和流变性质的影响。 将60、80、100 目黄花菜粉按添加量分别为2%、4%、6%、8%、10%制得牛肉糜凝胶,以未添加组为对照。结果表明,添加黄花菜粉能显著降低牛肉糜的蒸煮损失（p＜0.05）,牛肉糜凝胶的保水性和凝胶强度均随黄花菜粉添加量的增加而增强,黄花菜粉添加量为4%可显著增加牛肉糜持水性和凝胶强度。动态流变测量表明,牛肉糜的G′值经历3 个阶段,25 ℃～47 ℃时,添加不同目数黄花菜粉肉糜和空白对照组肉糜的储能模量G′值均缓慢升高;在47 ℃～60 ℃时,添加100 目黄花菜粉肉糜的G′值迅速上升;在60 ℃～80 ℃所有试验组牛肉糜的G′值快速上升。 添加量为4%的100 目黄花菜粉牛肉糜凝胶相对于其他组具有更好的品质特性,蒸煮损失（10.26%）、保水性（83.59%）、凝胶强度（2 448.25 g）、色泽（L*值48.19、a*值0.94、b*值5.35）、硬度（8 339.87 g）、弹性（0.92）、内聚性（0.68）、咀嚼性（6 527.52 g）和回复性（0.29）。     

高良姜精油微胶囊的制备及其对猪肉糜的保鲜效果

采用复凝聚法制备得到高良姜精油微胶囊并将其应用于猪肉糜的保鲜,研究不同质量分数微胶囊添加量对肉糜在10 d冷藏期间菌落总数、脂肪氧化程度(TBA值)和高铁肌红蛋白(Met Mb)含量的影响。结果表明:以壳聚糖和海藻酸钠为壁材制备的高良姜精油微胶囊能缓慢释放精油,对大肠杆菌、金黄色葡萄球菌和酵母菌有良好的抑菌效果。用于肉糜保鲜,与对照组相比,所有处理组均能抑制肉糜微生物生长,降低其TBA值和MetMb含量。其中,添加质量分数0.1%和0.2%微胶囊对肉糜有较好的保鲜作用且效果接近,而0.05%微胶囊保鲜效果不明显。结论:添加0.1%高良姜精油微胶囊可以提高肉糜品质,延长肉糜冷藏的货架期。     

气调包装对大菱鲆的冷藏保鲜效果

以大菱鲆为研究对象,通过不同气调包装（60% CO2＋5% O2＋35% N2、60% CO2＋30% O2＋10% N2、40% CO2＋30% O2＋30% N2）进行处理,测定其感官、菌落总数、pH值、挥发性盐基氮（TVB-N）值、硫代巴比妥酸（TBA）值、汁液流失率等指标变化,综合评价气调包装对冷藏大菱鲆的保鲜效果。结果表明：空气包装组大菱鲆冷藏货架期为4 d,60% CO2＋5% O2＋35% N2气调包装组的保鲜效果最佳,货架期约为8 d;气调包装中高体积分数的CO2抑菌效果较为明显,能有效延缓pH值、菌落总数与TVB-N值的升高,但较高含量的CO2会导致鱼肉汁液流失较为严重;在鱼肉脂肪氧化方面,O2较CO2作用更大,高含量的O2对脂肪氧化具有一定促进作用;60% CO2＋5% O2＋35% N2气调包装组冷藏贮存8 d,大菱鲆的菌落总数为6.69（lg（CFU/g））,TVB-N值为11.99 mg/100 g,TBA值为2.34 mg/100 g。总体结果表明,气调包装能显著延长冷藏大菱鲆货架期,具有良好的保鲜抑菌作用。     

不同薄膜包装对火龙果贮藏品质和生理特性的影响

为研究不同薄膜包装对火龙果贮藏品质及生理特性的影响,以‘紫红龙’火龙果为试材,采用聚乙烯保鲜袋（Polyethylene,PE）、聚氯乙烯保鲜袋（Polyvinyl chloride,PVC）、聚乙烯微孔保鲜袋（Polyethylene microporous,WK）3种薄膜包装对果实进行处理,包装后于(6±1) ℃下进行贮藏。结果表明:与对照（CK）相比,不同薄膜包装均能延缓火龙果果实的失重率及腐烂率上升,并推迟呼吸高峰的出现,抑制火龙果可溶性固形物（Total soluble solids,TSS）、可滴定酸（Titratable acid,TA）、可溶性蛋白、可溶性糖、维生素C（Vitamin C,V_C）和还原型谷胱甘肽（Glutathione,GSH）含量的下降,减少丙二醛（Malondialdehyde,MDA）、超氧阴离子（O₂·?）的积累,提高超氧化物歧化酶（Superoxide dismutase,SOD）、过氧化氢酶（Catalase,CAT）和过氧化物酶（Peroxidase,POD）的活性。其中,在贮藏30 d时,CK、PVC、WK、PE组的火龙果腐烂率分别为44.44%、33.33%、22.22%、11.11%。采后用PE薄膜包装处理火龙果的保鲜效果最好,可以有效延缓火龙果采后果实品质劣变,更利于果实货架品质的保持。     

玉米蛋白水解物对生鸡肉糜脂质氧化的影响

玉米蛋白粉是玉米湿法生产淀粉的主要副产物。以玉米蛋白粉为原料,对其先进行高温蒸煮预处理,然后采用碱性蛋白酶和复合蛋白酶对其进行双酶顺序水解,制得具有抗氧化活性的蛋白水解物,将其添加到生鸡肉糜中,研究肉糜的过氧化值(PV值)、硫代巴比妥酸值(TBA值)、巯基含量、盐溶性蛋白含量(SSP值)和感官评价的变化情况,考察玉米蛋白水解物对生肉糜脂质氧化的影响。结果表明:玉米蛋白水解物的水解度达到29.5%,抗氧化活性达到599.11U/mL;肉糜中玉米肽的添加延缓了脂质的氧化,且玉米肽添加量的不同对各指标有着不同程度的影响,其中,含0.05%玉米肽的肉糜脂质氧化程度最弱,具有良好的抗氧化效果。     

低温等离子体对金鲳鱼蛋白质和脂质氧化的影响

为研究低温等离子体处理条件对金鲳鱼中蛋白质和脂质氧化的影响,采用不同低温等离子体处理时间、处理电压、处理次数、处理后放置时间和处理方式来处理新鲜金鲳鱼,分析样品处理前后的羰基含量、总巯基含量、蛋白表面疏水性和硫代巴比妥酸反应物（thiobarbituric acid reactive substances,TBARS）值的变化。结果显示,在处理电压升高、处理时间延长时,低温等离子体能够增加金鲳鱼中羰基含量、蛋白表面疏水性和TBARS值,降低其巯基含量;当总处理时间为180 s,处理2次～4次,鱼肉脂质和蛋白质氧化程度显著低于处理1次。上述结果表明,高电压、长时间和多次数的低温等离子体处理对金鲳鱼中脂质和蛋白质氧化具有促进作用,同时延长处理后的放置时间也能够加速其氧化。因此,控制和优化各种处理条件,是推进低温等离子体在金鲳鱼保鲜包装中应用的关键。     

琥珀酸钠对牛肉糜色泽及高铁肌红蛋白含量的影响

在牛肉糜中加入0、4、6、8mmol/L的琥珀酸,研究其对牛肉糜pH、颜色、Mb和MetMb含量、TBARS的影响,以揭示琥珀酸-琥珀酸脱氢酶体系在MetMb还原中的作用.结果显示:琥珀酸添加对牛肉糜pH没有影响,低浓度琥珀酸(4～6mmol/L)可提高红度值和Mb含量,降低MetMb含量,但对肉的脂肪氧化没有抑制作用.     

Evaluation of cholesterol and lipid oxidation in raw and cooked minced beef stored under oxygen-enriched atmosphere

Oxygen-enriched modified atmosphere packaging (MAP) represents an important means to stabilize meat colour but may lead to an increase in lipid oxidation, influencing the acceptability and safety of the product. In this work, the effect on cholesterol and lipid susceptibility to oxidation was investigated in commercial minced beef held under MAP (80% O(2)/20% CO(2)). Cholesterol oxidation products (COPs), peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) were determined, before and after pan frying, at 1, 8 and 15 days since packaging under refrigerated storage (3-4°C). 7α-Hydroxycholesterol, 7β-hydroxycholesterol and 7-ketocholesterol were the more abundant COPs identified. COPs significantly increased in raw beef during storage: after 1, 8 and 15 days since packaging COPs were at the levels of 10.4, 30.7 and 60.5μg/g of fat, respectively. Cooking did not affect cholesterol oxidation in freshly packaged minced beef but led to a rise in COPs amount with respect to raw muscle after 8 and 15 days of storage. The trend in cholesterol oxidation reflected the progressive increase in lipid peroxidation rate brought by MAP conditions.     

Effect of dietary vitamin E supplementation, fat level and packaging on colour stability and lipid oxidation in minced beef

The effect of addition of vitamin E (2025 IU animal(-1) day(-1)) to the diet of beef bulls on the colour stability and lipid oxidation of minced beef was studied. Control and enriched diets were provided for the last 136 days before slaughter. Batches of freshly minced meat were prepared containing approximately 1.3 and 22.2 wt% fat, respectively. Half of the samples of minced meat from control (CON) and supplemented (SUP) beef were packaged on trays with oxygen-permeable over wraps and half in modified atmosphere (MA) packs (initial gas mixture: O(2)/CO(2)/N(2)=65/25/10). The minced beef was stored for 10 days at 7°C in an illuminated environment. The SUP meat at both fat levels was consistently more resistant to lipid oxidation than was the CON meat. The additional vitamin E had a greater anti-oxidant effect for the lean meat product. MA packaging in comparison to the oxygen-permeable foil over-wrap did increase lipid oxidation, the effect being most pronounced for the CON meat. A sensory panel considered the colour of the lean SUP meat during display as more attractive than that of lean CON meat, irrespective of packaging. A similar effect was observed occasionally for the relatively fat minced meat. These subjective findings were confirmed by objective assessment of colour. The stability of the colour of the MA packed meat was better than that of the oxygen-permeable foil-wrapped meat. Microbial growth patterns of enriched and control meat were similar. MA packaging retards the multiplication of mesophilic aerobic spoilage micro-organisms and Enterobacteriaceae.     

The combined effect of antioxidants and modified atmosphere packaging on protein and lipid oxidation in beef patties during chill storage

Effect of rosemary extract and ascorbate/citrate (1:1) in combination with modified atmosphere packaging (100% N(2), 80% O(2)/20% N(2)) on protein and lipid oxidation in minced beef patties during storage in the dark for up to 6 days at 4°C was investigated. A high level of oxygen in the packaging atmosphere was found to increase both lipid and protein oxidation during storage as evaluated by TBARS analysis of secondary lipid oxidation products and by 2,4-dinitrophenylhydrazine derivatization of protein carbonyls. Both antioxidant systems tested were found to inhibit lipid oxidation but not protein oxidation. In contrast, ascorbate/citrate was found to promote protein oxidation. Rosemary extract was found to regenerate or protect α-tocopherol whereas the packaging atmospheres had no effect on α-tocopherol stability. In high oxygen atmospheres both antioxidants protected the fresh red meat colour with ascorbate/citrate being more efficient than the rosemary extract, whereas no effect of antioxidant on meat colour was found in beef patties stored in 100% nitrogen.     

Cholesterol and lipid oxidation in raw and pan‐fried minced beef stored under aerobic packaging

BACKGROUND: The type of packaging atmosphere has been reported as a technological factor that consistently affects the quality of lipid fraction in meat. Oxidation of cholesterol and lipids was evaluated before and after pan frying in commercial refrigerated minced beef stored under aerobic atmosphere for 1 and 8 days. RESULTS: In raw beef, cholesterol and lipid oxidation developed at a slow rate. Cholesterol oxidation products (COPs) did not significantly vary (～8 µg COPs g^?1 of fat) over 8 days, while in the same period thiobarbituric acid reactive substances (TBARS) less than doubled (from 0.7 to 1.2 malondialdehyde equivalents kg^?1 of muscle). Pan frying did not influence the oxidative degree in the fresh product but consistently catalyzed cholesterol oxidation in stored beef. A significant increase was assessed in beef at the end of storage: from 8.6 to 30.0 µg COPs g^?1 of fat in raw and cooked beef, respectively. CONCLUSION: Aerobic packaging did not appear as a pro‐oxidant factor in fresh minced beef with a good oxidative quality during a short period of refrigerated storage. Copyright © 2010 Society of Chemical Industry     

The effect of oxygen level and exogenous α-tocopherol on the oxidative stability of minced beef in modified atmosphere packs

The effect of oxygen level (20, 40, 60 and 80%) in modified atmospheres on the oxymyoglobin content of intact and minced beef (M. semimembranosus, SM) was evaluated. There was no significant difference in the oxymyoglobin content of minced SM stored for up to 4 days in modified atmosphere packs containing 20, 40, 60 or 80% O(2). After 7 days, oxymyoglobin in minced SM decreased significantly (P?0.05) with decreasing oxygen level but by day 10 all samples had similarly low oxymyoglobin contents. Lipid oxidation increased significantly (P?0.05) between day 7 and 10 of storage in minced SM stored in modified atmospheres containing 40, 60 or 80% O(2). Oxymyoglobin and lipid oxidation occurred in intact SM but the extent of oxidation was lower than for minced SM. Exogenous α-tocopherol, dispersed in olive oil and added to minced SM (300 and 3000 mg α-tocopherol/kg lipid), had no significant effect on Hunter 'a' values when the samples were stored in low (20%) or high (80%) oxygen atmospheres. Exogenous α-tocopherol addition led to a significant reduction in lipid oxidation (P?0.05) in minced SM stored in high but not in low oxygen atmospheres.     

Effect of Fe2+, Salt, Cooking and Shredded CoffiR on Thiobarbituric Acid (TBA) Numbers in Ground Beef

Presence of ferrous iron (Fe²⁺) and/or salt (NaCl) in ground beef followed by cooking and storage resulted in marked increases in lipid oxidation as measured by TBA values. Addition of an edible collagen film (Coffi^R) to minced fresh beef did not influence TBA values. Cooking fresh ground beef resulted in lowering of TBA values (when compared to raw beef), but TBA values increased more rapidly and to a greater extent in cooked beef than in raw samples during 7 days refrigerated storage.     

Display life of beef packaged with an antioxidant active film as a function of the concentration of oregano extract

Fresh beef steaks were packaged with a new antioxidant active system containing increasing concentrations (0.5, 1, 2 and 4%) of an oregano extract. Control samples were packaged without the active film. Additional samples were sprayed with the extract and packaged as the control samples. Packages were filled with a 80%O(2)/20%CO(2) atmosphere and displayed under illumination (14 h) at 1 ± 1 °C for 28 days. Metmyoglobin formation, lipid oxidation (TBARS), instrumental colour (CIE a*) and sensory colour, discoloration, off-odour and oregano smell were determined. Active packaging significantly (P < 0.05) enhanced oxidative stability of beef steaks, depending on the oregano concentration of the active film. The display life of beef samples demonstrated that at least 1% oregano was needed for obtaining a significant increase of display life from 14 to 23 days. A concentration of 4% gave rise to unacceptable oregano smell. As a consequence, most suitable oregano extract concentrations for optimum active packaging in this system should be within the range 1-2%.     

喷雾冷冻干燥对葛仙米藻胆蛋白抗氧化特性的影响

研究喷雾冷冻干燥对葛仙米藻胆蛋白抗氧化特性的影响,并与冷冻干燥技术进行比较。主要测定ABTS+ ·、铁还原抗氧化能力(FRAP)、对羟自由基( ·OH)清除作用和H2O2诱导的脂质过氧化的抑制作用,结果发现,喷雾冷冻干燥(SFD)对葛仙米藻胆蛋白的抗氧化特性有一定的影响,在基于电子转移和氢原子转移的抗氧化测定方法中,SFD与冷冻干燥(FD)制备的样品差异不明显,但在基于活性氧自由基清除的测定方法中,SFD显著优于FD。表明SFD非常适合于高活性成分的干燥。     

气体结合高静压对干锅藕片贮藏期品质及微生物的影响

研究气体结合高静压(high hydrostatic pressure,HHP)处理对干锅藕片的货架期及贮藏品质的影响。测定充气包装后经高静压处理的干锅藕片在贮藏过程中微生物菌落总数、质构、色差、油脂过氧化值的变化及感官评价。结果表明:充CO_2结合高静压(CO_2-HHP)处理的干锅藕片贮藏期较充N_2、充CO_2、真空包装结合高静压(vacuum-HHP)处理、充N_2结合高静压(N_2-HHP)处理长,且第一循环硬度保持在14 000 g左右,b*值变化在2以内CO_2-HHP处理的干锅藕片在贮藏期内感官评价始终较好。这为低酸性食品的保藏提供了新的思路与方法。     

Antioxidative/Antimicrobial effects of galangal and alpha-tocopherol in minced beef

The antioxidant and microbial stabilities of galangal (Alpinia galanga) extract in raw minced beef were examined at 4 +/- 1 degree C. Raw minced beef containing galangal extracts (0 to 0.10%, wt/wt) were prepared. Lipid oxidation during refrigerated storage was assessed by monitoring malonaldehyde formation, using the thiobarbituric acid reactive substances method. In minced beef, added galangal extract improved oxidative stability. Galangal extract at higher concentrations of 0.05% and 0.10% (wt/wt) were also found to extend the shelf-life of minced beef. Addition of alpha-tocopherol (0.02%, wt/wt) to galangal extract (0.05%, wt/wt) were observed to increase the oxidative but not the microbial stability of minced beef during the storage of 7 days. Galangal extract may prove useful in inhibiting lipid oxidation and increasing microbial stability of minced meat.