大麦粉改善生鲜湿面的品质特性

通过添加不同比例的大麦粉(10%~60%)配成大麦-小麦混合粉,研究大麦-小麦混合粉的糊化特性和面团的流变学特性以及生鲜湿面的色泽、蒸煮损失率、断条率、质构特性。结果表明,当大麦粉添加量30%时混合粉的峰值黏度、崩解值、最终黏度和回生值升高幅度最大,升幅分别为50 cP、42 cP、39.66 cP、31.67 cP;生鲜湿面的硬度、内聚性和回复性分别升高了23.77%、6.85%、8.64%;拉断力和拉伸距离分别降低了13.80%、70.22%;在大麦粉添加量40%时,生鲜湿面的蒸煮损失率和断条率分别提高了37.36%、10.83%。随大麦粉的添加比例升高,面团弹性模量、黏性模量增大,tanδ值降低;面片的亮度显著下降。综合考虑,大麦全粉添加比例小于30%时,混合粉仍具有较好的加工特性,生鲜湿面的整体品质可被接受,更高比例的加入会导致生鲜湿面蒸煮损失率和硬度显著升高。     

Diversity in properties of seed and flour of kidney bean germplasm

The genetic diversity in seeds (physicochemical, hydration, textural and cooking properties) and flours (pasting and gel texture) among kidney bean lines was studied. A wide range of variation was observed for yield and yield-related traits. Seed weight, volume, density, hydration capacity, hydration index, swelling capacity, cooking time and amylose content ranged from 10.2 to 51.7 g/100 seeds, 14 to 46 ml/100 seeds, 0.51 to 2.15 g/ml, 0.03 to 0.62 g/seed, 0.16 to 0.97, 1.24 to 1.93 ml/seed, 50 to 120 min, and 0.09% to 5.02%, respectively. Hardness, cohesiveness, gumminess, springiness and chewiness of hydrated seeds ranged from 0.81 to 2.03 g, 0.18 to 0.48, 0.20 to 0.97 g, 0.31 to 0.51 and 0.08 to 0.43 g, respectively. Pasting temperature, peak viscosity, breakdown, final viscosity and setback ranged from 79 to 95 °C, 402 to 3235 cP, 9 to 393 cP, 862 to 5311 cP, and 363 to 2488 cP, respectively. Hardness, cohesiveness, gumminess, springiness, chewiness and adhesiveness of flour gels ranged from 3.9 to 5.3 g, 0.52 to 0.76, 1.47 to 23.52 g, 0.91 to 0.99, 3.21 to 23.91 and 13.2 to 178.5 g s, respectively.     

Effects of Frozen Storage and Cooking on Lipid Oxidation in Chicken Meat

Fresh chicken breast and leg meat samples, which were frozen for 3 months or 6 months at −18°C, were cooked in microwave and convection ovens and then tested for levels of lipid oxidation. After 6 months storage, malonaldehyde in fat from meat samples, as measured by a TBA assay, modified to avoid sample autoxidation, increased 2.5 fold, while the fluorescence excitation (360 nm) and emission (440 nm) spectra increased an average of 34%. Fat from meat cooked in a convection oven averaged 83% higher malonaldehyde concentration and 21% higher fluorescence compared to levels before cooking. Levels of lipid oxidation products in fat from chicken breast and leg meat were not significantly different in microwave compared to convection oven cooking; but certain secondary fluorescent products were higher in meats cooked by convection oven.     

Injection of sodium chloride, sodium tripolyphosphate, and sodium lactate improves Warner-Bratzler shear and sensory characteristics of pre-cooked inside round roasts

Paired inside rounds (n=30 pairs) were removed from randomly selected USDA Select quality grade carcasses to examine the effects of injecting a solution of sodium lactate, sodium tripolyphosphate, and sodium chloride on Warner-Bratzler shear force, cooking loss, lipid oxidation, and sensory characteristics of pre-cooked beef. Injected treatments were more tender (P<0.05) than control products, as measured by Warner-Bratzler shear force and consumer sensory panel ratings. Injected treatments had lower (P<0.01) cooking and re-heating loss percentages when compared to control samples. Lipid oxidation in injected treated samples was significantly reduced as compared to control meat samples. Results of lipid oxidation also revealed that 14-day samples were less (P<0.01) than 0-day samples. Results of this experiment have shown that injection of this solution enhanced sensory panel characteristics, and decreased WBS values and cooking loss.     

Genotypic diversity in physico-chemical,pasting and gel textural properties of chickpea (Cicer arietinum L.)

Twenty chickpea cultivars were evaluated for genetic diversity in seeds (physical, hydration and cooking), flours (composition, pasting and gel textural) and starch (swelling, thermal, amylose content and amylopectin structure) properties. Frequency distribution and principal component analysis revealed significant differences among the cultivars studied. Pasting temperature, peak viscosity, breakdown, final viscosity and setback of flours ranged from 75.0 to 87.1 °C, 564 to 853 cP, 32 to 123 cP, 573 to 969 cP, and 84 to 185 cP, respectively. Amylose content of starch ranged from 28.26% to 52.82%. Amylopectin unit chains of DP 6–12, 13–18, 19–24 and 25–30 ranged from 36.2% to 43.25%, 36.44% to 38.68%, 14.86% to 18.22% and 4.95% to 6.9%, respectively. To establish the relationships between different properties Pearson correlation coefficients (r) were computed. Cluster analysis for grain and flour characteristics was also done to see the association between chickpea cultivars.     

可微波冷冻预油炸鸡肉的风味物质研究

采用同时蒸馏萃取法(SDE)和固相微萃取法(SPME)与气谱-质谱联用(GC-MS)结合提取并检测鸡肉在腌制、油炸和微波复热过程中风味物质的变化规律.从实验结果的重复性和检测化合物数量两个方面分析,SPME法检出风味物质化合物57种,SDE法为45种,SPME法测得的风味物质数量多于SDE法,故对SPME法进行后续实验,实验得出鸡肉加工过程的挥发性风味物质总计为110种,其中原肉中检测出36种,腌制后检测出48种,油炸后检测出46种,微波后为57种.加工过程部分改变了主要风味物质的种类和比例,美拉德反应对于鸡肉烧烤香味起决定性的作用,脂质氧化降解对鸡肉特征风味的形成起到促进作用,油炸加工和微波二次烹饪对鸡肉整体香味构成具有重要的作用.     

Selected Quality and Shelf Life of Eggs Coated with Mineral Oil with Different Viscosities

ABSTRACT:  Selected quality and shelf life of eggs coated with mineral oil having 6 different viscosities (7, 11, 14, 18, 22, and 26 cP) were evaluated during 5 wk of storage at 25 °C. As the storage time increased, weight loss and albumen pH increased whereas Haugh unit and yolk index values decreased. After 5 wk of storage, eggs coated with 11, 14, 18, 22, or 26 cP oil possessed better quality than the control noncoated eggs and eggs coated with 7 cP oil. Oil coating, irrespective of viscosities, did not improve the emulsion capacity. There was an observable trend that coating with 26 cP oil was more effective in preventing weight loss and in maintaining the Haugh unit of eggs compared with coating with other viscosities of mineral oil. Based on the Haugh unit, the grade of noncoated eggs changed from "AA" at 0 wk to "C" after 3 wk whereas that of 26 cP oil-coated eggs from "AA" at 0 wk to "A" at 3 wk and "B" at 5 wk of storage. Coating with 26 cP oil reduced the weight loss of eggs by more than 10 times (0.85% compared with 8.78%) and extended the shelf life of eggs by at least 3 more weeks compared with the noncoated eggs.     

Vacuum-Packaged Precooked Pork from Hogs Fed Supplemental Vitamin E: Chemical, Shelf-Life and Sensory Properties

Precooked longissimus chops and semimembranosus/adductor roasts from pigs (n = 30) given no supplemental vitamin E (CON) or supplemented with 100 mg vitamin E/kg diet (VITE) were evaluated for lipid oxidation, microbial growth, sensory characteristics, cooking/storage losses and reheating losses. Chops and roasts were vacuum packaged, precooked to 60°C and stored at 2°C for 0, 7, 14, 28, or 56 days. Lipid oxidation was lower in VITE chops and roasts than in CON chops and roasts. Off-flavor intensity scores were more acceptable and storage/ cooking losses were lower for VITE roasts than for CON roasts. Supplementation of vitamin E in a swine diet provided added protection against lipid oxidation and precooking pork under vacuum provided a palatable product with a shelf-life of 56 days.     

不同杂粮添加对籼米粉粉质特性及挤压米粉品质特性的影响

本文选择绿豆、荞麦、高粱、薏米四种杂粮分别添加到籼米粉中,替代比例为25%。通过快速黏度测定仪、动态流变仪、质构仪和扫描电镜,研究了杂粮添加对米粉糊化特性、流变特性、凝胶质构和微观结构等特性的影响。利用挤压重组技术生产挤压杂粮米粉,研究了杂粮添加对挤压米粉蒸煮特性、质构特性的影响。结果表明,杂粮粉与籼米粉混合后,荞麦混合粉在淀粉糊化过程中表现出最高的峰值黏度和最终黏度,分别为4241和4705 cP,而薏米混合粉峰值黏度和回生值最低,分别为2438和1369 cP;添加杂粮后的凝胶结构呈现出较多的孔状,其中荞麦粉混合凝胶的硬度和弹性值最大,分别为16.60 g和0.89;添加杂粮后,挤压米粉的膨胀率、蒸煮损失、断条率均有所增加;添加荞麦粉后米粉的质构特性接近籼米米粉,而添加薏米粉的米粉质构特征值表明挤压米粉的品质显著降低(p<0.05)。利用挤压技术开发挤压杂粮米粉不仅可以提高米粉的营养价值,同时也有助于推动传统主食食品米粉的工业化发展进程。     

不同热加工温度对牛肉干脂肪酸及脂肪氧化的影响

采用气相色谱-质谱联用技术,测定牛肉干中脂肪酸的组成,研究失水率相同时,不同干燥温度（25、55 ℃）及熟制温度（85、150 ℃）对牛肉干中脂肪酸组成和脂肪氧化的影响。结果表明：经热加工后,牛肉干的脂肪酸含量和脂肪氧化程度均有不同程度的变化。经55 ℃干燥后,不饱和脂肪酸（unsaturated fatty acid,UFA）、多不饱和脂肪酸（polyunsaturated fatty acid,PUFA）和单不饱和脂肪酸（monounsaturated fattyacid,MUFA）含量显著低于25 ℃干燥（P＜0.01）,饱和脂肪酸（saturated fatty acid,SFA）含量显著高于25 ℃干燥（P＜0.01）,且脂肪氧化程度低于25 ℃干燥;熟制阶段,25 ℃干燥后熟制,SFA、UFA、MUFA和PUFA含量变化不显著（P＞0.05）,而55 ℃干燥后,经150 ℃熟制,UFA、MUFA和PUFA含量显著低于85 ℃熟制（P＜0.01）,SFA含量显著高于85 ℃熟制（P＜0.01）,且脂肪氧化程度高。综上所述,不同干燥温度及熟制温度对牛肉干脂肪酸及脂肪氧化的影响不同,干燥阶段,较高温度（55 ℃）干燥对牛肉干脂肪氧化的影响小于25 ℃干燥;熟制阶段,较低温度（85 ℃）熟制对牛肉干脂肪氧化影响较小。因此,55 ℃干燥、85 ℃熟制得到的牛肉干产品,其UFA、MUFA和PUFA含量最高,SFA含量最低,脂肪氧化程度最小,牛肉干营养价值损失最小。     

Lipid Oxidation in Cooked Pork as Affected by Vitamin E, Cooking and Storage Conditions

The individual and combined effects of muscle vitamin E level, cooking conditions (duration, temperature and rate) and packaging on lipid oxidation in refrigerated cooked pork were examined. Oxidative stability following cooking was higher in pork with a higher vitamin E level (p<0.01), cooked at a lower cooking temperature (p<0.01), cooked for a shorter time (p<0.01), cooked at a faster cooking rate (p<0.05) or stored in vacuum packs (p<0.01). Significant two-way and three-way interactions were observed between the effects of muscle vitamin E level, cooking conditions and packaging on lipid oxidation. Adopting more than one of these approaches to minimize lipid oxidation was more effective than adopting a single approach.     

Mechanisms of Docosahexaenoic and Eicosapentaenoic Acid Loss from Pacific Saury and Comparison of Their Retention Rates after Various Cooking Methods

The docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) contents of Pacific saury (Cololabis saira), a fatty fish and staple of the Japanese diet, have been reported to decrease after cooking. This study compared the DHA and EPA contents remaining in saury after grilling, pan‐frying or deep‐frying to center temperatures of 75, 85, or 95 °C, and examined physical loss, lipid oxidation, and thermal degradation as mechanisms of DHA and EPA loss. Temperature changes inside the saury were monitored using thermocouples, while DHA and EPA contents, oxygen radical absorbance capacity, and measurements of lipid oxidation (that is, carbonyl value and thiobarbituric acid value) were determined chemically. Visualization of temperature distribution inside fish samples during cooking revealed large differences in heat transfer among cooking methods. True retention rates in grilled (DHA: 84 ± 15%; EPA: 87 ± 14%) and pan‐fried samples (DHA: 85 ± 16%; EPA: 77 ± 17%) were significantly higher than deep‐fried samples (DHA: 58 ± 17%; EPA: 51 ± 18%), but were not affected by final center temperatures despite differences in cooking times. Physical loss via cooking losses (grilling and pan‐frying) or migration into frying oil (deep‐frying) accounted for large quantities of DHA and EPA loss, while lipid oxidation and thermal degradation did not appear to be major mechanisms of loss. The antioxidant capacity of saury was not significantly affected by cooking treatments. The results of this study suggest that minimization of physical losses during cooking may increase DHA and EPA contents retained in cooked Pacific saury.     

Physicochemical Characterization of Selected Sweet Potatocultivars and Their Starches

The uses of sweet potato tubers rely on the physicochemical and functional properties of its starch. The different properties studied from 14 lines include cooking quality, extractable starch, dry matter, starch, sugar, carotenoids, and anthocyanin. The properties of extracted starch like swelling volume, solubility, amylose content, clarity of paste, rheological properties were examined. The organic matter content of different lines almost remained the same. Starch content of the tubers was greater than 20% and the sugar content ranged from 1–3%. The extractable starch was in the range of 16–21%. The anthocyanin content was high for ST- 13, while ST- 14 was rich in carotene. The swelling volume was comparatively low and the solubility ranged from 8.81–13.65%. Most of the starches examined in this present study displayed excellent viscosity properties with peak viscosity greater than 3000 cP. This study revealed that many lines have excellent potential for use as nutritive and calorific food and as industrial raw material.     

Packaging and Irradiation Effects on Lipid Oxidation and Volatiles in Pork Patties

Raw-meat patties were prepared from three pork muscles, irradiated in different packaging environments, and stored for 0 or 3 days before cooking. Lipid oxidation by-products were formed in the raw meat during storage and the baseline lipid oxidation data of raw meat was used to measure the progression of lipid oxidation after cooking. Thiobarbituric acid-reactive substances (TBARS) and volatiles data indicated that preventing oxygen exposure after cooking was more important for cooked meat quality than packaging, irradiation, or storage conditions of raw meat. Propanal, pentanal, hexanal, 1 -pentanol, and total volatiles correlated highly (P < 0.01) with TBARS values of cooked meat. Hexanal and total volatiles represented the lipid oxidation status better than any other individual volatile components.     

加热温度和时间对真空低温烹饪鸡胸肉脂肪与蛋白质氧化的影响

在不同温度（65～85 ℃）和时间（2～14 h）条件下对鸡胸肉进行真空低温烹饪,以处理后鸡胸肉的酸价（acid value,AV）、硫代巴比妥酸（thiobarbituric acid,TBA）值、共轭二烯烃过氧化物（conjugated diene hydroperoxide,CDHP）含量、蛋白质羰基和巯基含量为指标,分析加热温度和时间对真空低温烹饪鸡胸肉脂肪和蛋白质氧化的影响。结果表明：相同加热温度下,鸡胸肉的CDHP含量随时间的延长而增加,85 ℃加热时,随着时间的增加,鸡胸肉的CDHP含量增加最为显著（从0.51 mmol/kg增加到2.51 mmol/kg）;TBA值在烹饪的起始阶段呈上升趋势,并且65、75 ℃加热条件下,鸡胸肉的TBA值上升速率明显大于85 ℃加热的样品,加热6～14 h过程中,TBA值呈现下降的趋势;随着加热温度的升高,鸡胸肉的AV上升速率显著增加（P＜0.05）,在75、85 ℃加热时,样品的AV远远大于65 ℃加热时的AV;在所有加热温度下,随着时间的延长,蛋白质巯基含量均不断下降,羰基含量均呈不断上升趋势,加热至14 h时,鸡胸肉中的蛋白质羰基含量接近烹饪之前的5 倍。总之,加热温度的升高和加热时间的延长对真空低温烹饪鸡胸肉的脂肪和蛋白质氧化均有显著影响（P＜0.05）。     

Effect of different cooking methods on lipid oxidation and formation of volatile compounds in foal meat

The influence of four different cooking methods (roasting, grilling, microwaving and frying) on cooking loss, lipid oxidation and volatile profile of foal meat was studied. Cooking loss were significantly (P < 0.001) affected by thermal treatment, being higher (32.5%) after microwaving and lower after grilling (22.5%) and frying (23.8%). As expected, all the cooking methods increased TBARs content, since high temperature during cooking causes increased oxidation in foal steaks, this increase was significantly (P < 0.001) higher when foal steaks were microwaved or roasted.     

Lipid oxidation of beef fillets during braising with different cooking oils

Effects of braising without oil and with different cooking oils (olive oil, corn oil and partially hydrogenated plants oil) on the susceptibility to lipid oxidation in beef fillets (psoas major) were evaluated. The beef fillets were pan-fried without oil or with the respective oils for five min, followed by 90 min steam cooking (braising). Lipid oxidation status of the samples and the cooking residues was evaluated by peroxide value (PV), acid value (AV), p-Anisidine value (p-AnV), as well as the alteration of the tocopherol content. Total lipids and the individual fatty acid pattern were analyzed in order to determine the impact of the frying medium as well as the cooking procedures on the fat of the braised samples. The decrease in PV simultaneous with the significant increase in p-AnV indicated the progression of lipid oxidation. Tocopherol and fatty acid contents of all the investigated samples exhibited modifications mainly due to the influence of the frying medium and braising process. Although there was a significant change in lipid oxidation parameters, there is no risk in consuming such braised meat.     

烹制方法对猪肉脂质氧化和挥发性风味物质的作用研究

研究对比了4种烹制方法(煮制、烤制、微波及油炸制(大豆油、花生油和葵花油))对猪肉脂质氧化及挥发性风味成分的影响。结果表明:烹制能够促进猪肉的脂质氧化,经不同方式烹制后,熟制猪肉的过氧化值(POV)和硫代巴比妥酸值(TBA)显著增加(P0.05)。不同熟制猪肉之间脂质氧化程度存在显著性差异(P0.05),其中烤制猪肉的脂质氧化程度最高,其次为微波和水煮,而炸制猪肉的氧化程度最低。气相色谱-质谱(GC-MS)联用技术从熟制猪肉中共分离鉴定出68种挥发性风味成分,主要包括醛类、脂肪烃类、醇类、酮类、酯类等,总挥发性风味化合物含量在221.09(大豆油炸制猪肉)-1084.61 AU×106/g(煮制猪肉)之间。醛类是主要的化合物,占总挥发性风味成分的73.78(葵花油炸制猪肉)-78.79%(烤制猪肉),而己醛是最主要的醛类物质。TBA值与醛类、醇类及总挥发性风味物质呈显著正相关(p0.05),而POV值与挥发性风味物质的相关性不显著(p0.05)。主成分分析法(PCA)能够很好地区分经不同烹制方法得到的熟猪肉。     

Hypochlorite oxidation of field pea starch and its suitability for noodle making using an extrusion cooker

The effect of hypochlorite oxidation on the Brabendar pasting properties of field pea starch and the suitability of native and oxidized starch for noodle making by extrusion cooking were investigated. Field pea starch was oxidized with sodium hypochlorite at a level of active chlorine ranging from 0.89 to 3.28% (starch db). The degree of oxidation was determined and expressed in terms of percentage of carboxyl and carbonyl groups, which ranged from 0.02 to 0.38% and 0.06 to 0.19%, respectively. Starch recovery and peak viscosity, hot paste viscosity, cool paste viscosity, and setback of oxidized starches decreased with increasing degree of oxidation. The cooking quality attributes of noodles prepared from native field pea starches were acceptable but were negatively influenced by hypochlorite oxidation. Substitution of potato starch (40%, db) for field pea starch yielded more glossy noodles with better cooking quality. It was also observed that Brabendar pasting properties had high correlations with noodle quality characteristics.     

Effect of frozen storage duration and cooking on physical and oxidative changes in M. Gastrocnemius pars interna and M. Iliofiburalis of Rhea americana

This study was conducted to evaluate the effect of frozen storage time (30, 60, 90 or 180 days) and cooking (100 °C, 30 min) on the physical characteristics and oxidative stability of M. Gastrocnemius pars interna (GN) and M. Iliofiburalis (IF) of rhea americana. Physical parameters measured included thawing and cooking loss, colour parameters (L*a*b*), while oxidation was assessed by determining the TBA-RS, carbonyl and aromatic amino acid content. Prolonged frozen storage of rhea meat decreased lightness (L*), yellowness (b*), and increased the discoloration parameter hue angle and redness a*. During storage, muscle IF was more prone to lipid and myoglobin oxidation than muscle GN. Cooking loss declined with the increase of storage time and was higher in GN than in IF muscle. With cooking, TBA-RS, carbonyl content, and aromatic amino acids (phenylalanine, tyrosine, and tryptophan) were highly affected, but the extent of oxidation ranged according to muscle and duration of frozen storage.