基于低场核磁共振研究不同解冻方式对冻猪肉食用品质的影响

本研究旨在从低场核磁共振（low field-nuclear magnetic resonance,LF-NMR）T2弛豫的角度探究不同解冻方式对冻猪肉食用品质的影响。以冷鲜肉（半腱肌,宰后27 h）作对照,测定冷藏解冻、微波-1解冻和微波-2解冻3 种解冻方式下冷冻猪肉的品质特性（解冻损失、蒸煮损失、持水能力（water holding capacity,WHC）、pH值、色泽、水溶性和盐溶性蛋白含量）,T2弛豫时间的水分分布情况及感官品质特性的变化。结果表明：微波-2解冻耗时最短,为5 min;微波解冻与冷藏解冻相比,具有更低的解冻损失率（P＜0.01）,其中微波-2的解冻损失率最低（5.31%）;并且相比于鲜肉,微波-2具有更高的WHC（30.99%）和更低的剪切力（19.49 N）;3 种解冻方式对肉样pH值无显著影响（P＞0.05）;微波解冻对肉样L*值、a*值、b*值、水溶性蛋白含量和盐溶性蛋白含量的影响均优于冷藏解冻,且与冷鲜肉更加接近;NMR T2弛豫的水分分布情况显示,冷藏解冻使冻猪肉中的不易流动水向自由水进行迁移,微波-1解冻则使冻猪肉中的自由水向不易流动水迁移,而微波-2解冻更倾向于使不易流动水向结合水迁移,这一定程度上解释了以上品质特性指标的差异性;感官评价结果显示微波-2解冻肉样各项评估指标评分与鲜肉更接近。由此可见,微波-2解冻能够更好地保持猪肉的食用品质。     

不同冻藏条件对鸡胸肉品质特性的影响

为研究不同冻藏条件对鸡胸肉品质特性的影响,本实验以新鲜鸡胸肉为原料,于-16、-26和-36 ℃分别冻藏1、2、3、4、5、6个月,分析比较不同冻藏温度和时间对鸡胸肉的系水力、色泽、蛋白质变性程度、嫩度、脂肪酸败及新鲜度的影响情况。结果表明,随着冻藏温度的升高及冻藏时间的延长,pH呈现先降低后升高的趋势,鸡胸肉的解冻损失率、蒸煮损失率、剪切力以及b*值也逐渐增加,L*值、总蛋白及肌原纤维蛋白溶解度显著降低(p<0.05),但对肌浆蛋白的溶解度无显著影响(p<0.05);a*值则在冻藏前1个月显著增加(p<0.05),但随后逐渐降低,且随着冻藏温度升高而减小(p<0.05)。衡量系水力指标的解冻损失和蒸煮损失结果,衡量色差的L*、a*和b*值以及衡量蛋白变性指标的三大蛋白溶解度和TBARS值与TVB-N值均表明,鸡胸肉在冻藏温度为-36~-26 ℃及冻藏时间为5个月内能有效维持较好的鸡胸肉食用品质。此外,各指标间的相关性分析表明,不同冻藏条件下解冻损失率、蒸煮损失率、剪切力、TVB-N值、TBARS值、a*值、b*值、蛋白溶解度与新鲜鸡胸肉呈现显著的差异(p<0.05),而pH、L*值与新鲜鸡胸肉差异不明显(p>0.05)。本文为快速发展的冷冻禽肉的加工及贮藏环境提供了理论依据。     

Effect of rapid thawing on the meat quality attributes of USDA select beef strip loin steaks

The objective was to determine the meat quality effects of rapidly thawing beef steaks in a water bath. Frozen beef strip loins (n = 24) were cut into steaks sequentially from the rib end and identified by anatomical location (anterior, middle, posterior) within the loin. Within location, steaks were randomly assigned to conventional (C; 18 to 20 h, 4 °C) or rapid thawing methods. Rapid thawing methods, fast (20 min, 20 °C) or very fast (11 min, 39 °C), were conducted in a circulating water bath. The physical, thawing, cooking, color, and texture characteristics of each steak were recorded. Data were analyzed as a randomized complete block design with a 3 thawing treatments × 3 locations factorial analysis with loin as a block. No location by thawing method interaction was detected (P > 0.05) for the measured variables. Compared to C steaks, rapidly thawed steaks exhibited lower thaw drip loss (P < 0.001) and higher a* values (P < 0.001). Thawing treatment did not influence L*, b*, cook yield, or shear force. Steaks from the posterior end had higher (P < 0.001) surface to volume ratios that may have contributed to the higher thaw loss (P < 0.01), longer cooking time (P < 0.001), lower cooking yield (P < 0.001), and higher shear force (P < 0.02) compared to steaks from the anterior and middle portions of the loins. These data indicate that beef steaks taken from the entire length of the loin can be rapidly thawed in a water bath following food safety guidelines with minimal impact on meat quality. Practical Application: Freezing rate and frozen storage effects on meat quality have been well documented; however, there is comparatively little information on the meat quality effects of rapid thawing within food safety guidelines. This study demonstrates that beef strip loin steaks can be rapidly thawed in as few as 11 min without affecting texture or cooking yield, while reducing thaw drip loss. Thus, rapid thawing may enhance the apparent juiciness of steaks for consumers and provide an effective method for maintaining consistent control of experimental conditions for researchers.     

等离子体活化水作为解冻介质对牛肉杀菌效能及品质的影响

目的:研究低温等离子体活化水（plasma-activated water,PAW）作为解冻介质对牛肉微生物安全及生鲜品质的影响。方法:采用射频等离子体发生装置,处理水量为300 mL,以高压电源处理时间（40、60、80、100、120 s）为试验因素,制备不同处理时长的PAW。将放置至常温（25 ℃）的PAW作为冷冻牛腱子肉的解冻介质,以介质与样品4:1的质量比例静置浸泡解冻10 min,测定牛肉和解冻介质中的菌落总数、亚硝酸根含量、pH,及牛肉保水性（汁液损失率、持水力）、脂质氧化和蛋白质流失状况。结果:随着等离子体活化水制备时间的延长,其减菌效果显著增强（P<0.05）,解冻后牛肉中的菌落总数可降低0.91 lg (CFU/g)。将等离子体活化水作为解冻介质可显著增强牛肉的持水力（P<0.05）,汁液损失率最多可降低1.83%,脂质氧化程度可降低0.0944 mg/kg,蛋白流失可减少0.085 mg/mL,牛肉经解冻后,亚硝酸根含量最高为3.38 mg/kg,仍小于定量限,解冻后肉品pH最大仅增加0.06,即该解冻方式并不会对牛肉的亚硝酸根、pH产生显著影响（P<0.05）。本研究为低温等离子体活化水在肉制品解冻方面的应用提供了一定的理论依据和数据参考。     

Meat quality and cooking attributes of thawed pork with different low field NMR T(21)

A relationship of low field NMR T(2) components to meat quality and cooking attributes of pork was investigated. Longissimus muscle was removed from 23 pig carcasses at 24h postmortem for meat quality measurements and cooking test. Frozen samples were classified into three groups by LF-NMR T(21) of thawed samples: A (<40ms), B (40-44ms) and C (>44ms). There were significant differences (P<0.05) in pH, lightness (L* value) and pressing loss among the three groups. Cooking time to attain 70°C was slightly lower in group C than the other groups. Shear force value of cooked samples was not affected by T(21). The component T(21) correlated (P<0.05) with L* value, muscle pH and pressing loss, while L* value correlated (P<0.05) with thawing loss and muscle pH. Therefore, combined LF-NMR and color measurements could be a good way to differentiate water holding capacity of pork.     

Meat and storage effects on processing characteristics of beef roasts

Two experiments were done to determine the effect of storage conditions and meat cut on the processing characteristics of beef roasts. The first experiment examined the effect of storage condition (fresh/frozen), cap on/off, thawing regime and holding time post thawing on purge, brine uptake, cook yield and colour of raw and cooked roasts. The second experiment examined the effect of meat cut (insides/flats) and chilled storage for up to 8 weeks on processing characteristics of roast beef. Purge was greater for insides stored frozen without cap and air thawed. Frozen thawed cuts had increased brine retention after injection, after tumbling and after cooking. Flats had less purge and higher cook yields when manufactured into roast beef. Raw and cooked colour was not significantly affected by most factors investigated. Raw meat was more red than meat that had been frozen.     

Thaw drip loss and protein characterization of drip from air-frozen,cryogen-frozen,and pressure-shift-frozen pork longissimus dorsi in relation to ice crystal size

Drip loss from thawed, pressure-shift-frozen longissimus dorsi pork was not different from drip loss from fresh meat samples, while cryogen-frozen (using liquid nitrogen at –70 °C) and air-frozen (–20 °C) pork both had significantly higher drip loss (12%) upon thawing when compared to pressure-shift-frozen and fresh pork (4%). Pressure-shift-frozen pork was discolored, with a significant decrease in CIE redness parameter a*, and showed signs of denaturation upon visual inspection. A high molecular weight protein band (Mw 97,000) characteristic for gel electrophoresis (SDS-PAGE) for drip from fresh, air-frozen, and cryogen-frozen pork was not present in drip from pressure-shift-frozen pork. Ice crystals in the frozen pork, as evaluated by image analysis of cavities in digitized pictures from light microscopy of 14 m-thick meat slices (cut transverse to the fiber direction) embedded in tissue wax following treatment with Carnoys fixative and ethanol, increased in the order: pressure-shift-frozen<cryogen-frozen<air-frozen pork. Meat structure, as evaluated visually following thawing, deviated from fresh meat structure only for pressure-shift-frozen pork. It is accordingly concluded that pressure denaturation of meat proteins is more important for structure appearance than growth of ice crystals, and that protein denaturation increases water-binding capacity in pressure-shift-frozen pork.     

Differentiation between fresh beef and thawed frozen beef

In order to prevent meat retailers offering thawed, imported frozen beef as fresh domestic beef, the method of Gottesmann and Hamm for differentiating between fresh and frozen/thawed meat is recommended. The principle of this method is based on the fact that freezing and thawing of meat results in a release of the enzyme β-hydroxyacyl CoA-dehydrogenase (HADH) from the mitochondrion into the sarcoplasm; an elevated HADH activity in the muscle press-juice indicates freezing and thawing of tissue. The HADH colour test of Gottesmann and Hamm was modified by replacing the electron-transmitter meldolablue by resazurin which results in a much higher colour stability after reaction with fresh meat extracts.     

反复冻融对缠丝兔加工过程中脂肪酸含量变化的影响

以反复冻融兔肉为原料,分析缠丝兔加工过程中的脂肪酸含量变化。结果表明：与新鲜原料兔肉对照,随着冻融次数增加,反复冻融原料兔肉及其腌制后和烘烤后的脂肪含量显著降低,硫代巴比妥酸值显著增加（P＜0.05）;原料兔肉检测出棕榈酸（C16∶0）、亚油酸（C18∶2）等脂肪酸,在缠丝兔加工过程中,脂肪降解产生了油酸（C18∶1）;反复冻融兔肉在腌制和烘烤后的脂肪酸也呈显著性变化（P＜0.05）;5 次冻融原料的缠丝兔脂肪含量最低（0.023 8%）、硫代巴比妥酸值最高（0.216 8 mg/kg）。表明兔肉反复冻融对缠丝兔的脂肪酸含量影响显著。     

基于低场核磁共振探究解冻过程中肌原纤维水对鸡肉食用品质的影响

本研究旨在基于低场核磁共振横向弛豫时间T2分析解冻过程中肌原纤维水的分布及流动性与鸡肉食用品质间的关联性。以冷鲜鸡胸肉（宰后32 h）为对照,采用冷藏解冻、微波解冻（微波-1、微波-2）与超声解冻（180、200 W）5 种不同方式解冻中心温度为－20 ℃的冻结鸡胸肉,测定肉样T2、品质特性指标并分析它们之间的相关性。结果显示：解冻过程中肉样的T2水分分布情况发生明显变化,与对照组相比,除微波-2解冻外,其余4 组解冻肉样均发生不易流动水T22（40～50 ms）向自由水T23（100～250 ms）迁移;同时,微波-2解冻与200 W超声解冻出现强结合水水分群T20（0～0.1 ms）;相关性分析表明,T20、T21和T22峰比例与肉样的持水能力、嫩度和多汁性呈极显著正相关（P＜0.01）,与解冻损失率、蒸煮损失率呈显著（P＜0.05）或极显著（P＜0.01）负相关;剪切力与T20峰比例呈显著负相关（P＜0.05）,与T22峰比例呈极显著负相关（P＜0.01）。解冻方式对肉样的外观和风味无显著影响（P＞0.05）,微波-2解冻肉样的质地与多汁性评分最接近于对照组,整体可接受性更高;冷藏解冻与超声解冻肉样的质地与多汁性更差,整体可接受性也更低。因此,本项研究结果表明在解冻过程中肌原纤维水的迁移情况对鸡肉品质具有显著影响,并且微波-2解冻程序能够更好地抑制解冻过程中肉品质的下降。     

解冻方式对近江牡蛎肉感官特征和理化指标的影响

为获得冻结牡蛎肉的最佳解冻方式,以解冻时间、感官评分、质构、色差、解冻损失率、蒸煮损失率、pH、挥发性盐基氮(Total volatile basic nitrogen,TVB-N)、硫代巴比妥酸(Thibabituric acid,TBA)和菌落总数为指标,研究自然解冻、静水解冻、冷藏解冻、超声波解冻和微波解冻5种解冻方式对近江牡蛎感官特征和理化指标的影响,并采用变异系数权重法对解冻后牡蛎肉品质进行综合评价。结果表明:自然解冻(128 min)与冷藏解冻(309 min)所需时间较长,解冻后牡蛎肉的感官评分最小,分别为4.6、4.4分;TVB-N、TBA和菌落总数较大。微波解冻(1.5 min)和超声波解冻(9 min)耗时较短,感官评分较高,分别为6.12、6.0分;TVB-N、TBA和菌落总数最小,但蒸煮损失率和解冻损失率较大。静水解冻所需时间31 min,感官评分(6.0分)较高,但TVB-N、TBA和细菌总数较大。综合评价结果显示,解冻时间(权重值为0.357)对牡蛎肉品质影响最大,微波解冻综合评分(0.548)最高,是理想的近江牡蛎肉解冻方式,但持水力较低,微波解冻条件仍需进一步研究。     

超声波解冻对鸡胸肉品质的影响

本实验旨在研究超声波解冻对鸡胸肉品质的影响。以15 ℃静水解冻组为对照组,在同样水温条件下,以 4 种不同功率（120、180、240、300 W）超声波解冻组为实验组,分析不同功率超声波解冻对鸡胸肉品质的影响。 结果表明：与对照组相比,超声波解冻后鸡胸肉红度（a*值）显著升高,解冻时间显著缩短,细菌总数显著降低 （P＜0.05）,但其解冻汁液流失率、T23（表征自由水）峰面积比显著升高（P＜0.05）,pH值、亮度（L*值）、总蛋 白溶解度和肌原纤维蛋白溶解度显著降低（P＜0.05）;与240 W和300 W超声波处理组相比,120 W和180 W超声波解 冻后鸡胸肉剪切力、总蛋白溶解度和肌原纤维蛋白溶解度显著升高（P＜0.05）,T23峰面积比显著降低（P＜0.05）, 而180 W超声波处理组细菌总数显著低于120 W处理组（P＜0.05）。综合分析,与静水解冻相比,超声波解冻工艺 可有效提高鸡胸肉解冻速率并显著改善新鲜度,但解冻后鸡胸肉蛋白质变性导致保水性较差,解冻汁液流失率高且 肉色偏暗,对解冻后鸡胸肉品质有一定的负面影响,其中180 W超声波解冻对鸡胸肉品质负面影响最小。     

不同解冻方式对伊拉兔肉品质特性的影响

比较自然空气解冻、低温解冻、流水解冻、微波解冻和超声波解冻5 种解冻方式对伊拉兔肉品质特性的影响,分析兔肉解冻过程中基本食用品质、全质构特性、总挥发性盐基氮（total volatile basic nitrogen,TVB-N）值和硫代巴比妥酸反应物（thiobarbituric acid-reactive substance,TBARS）值的变化。结果表明,伊拉兔肉的食用品质、质构特性、TVB-N值和TBARS值之间具有显著的相关性,不同解冻方式对兔肉品质变化有一定的影响,解冻后蒸煮损失率、剪切力、TVB-N值、TBARS值、a*值、b*值、硬度、胶着性和咀嚼性与对照组出现明显的差异（P＜0.05）,pH值、L*值、内聚性、弹性与对照组差异不显著（P＞0.05）。5 种解冻方式中,微波解冻能较好地保持兔肉的嫩度和色泽,且通过微波解冻后的兔肉其蒸煮损失率、pH值、TVB-N值和TBARS值最低,但解冻损失率较高,质构特性较差。与其他几种解冻方式相比,微波解冻能够较好地保持兔肉的品质,但解冻条件仍需要进一步的研究。     

不同超声辅助解冻方式对海鲈鱼品质的影响

将五种解冻处理的海鲈鱼(超声微波解冻、超声远红外解冻、超声欧姆解冻、超声真空解冻和超声解冻)与新鲜鱼肉进行比较,研究了不同解冻方式对海鲈鱼品质的影响。本文主要分析了解冻后鱼肉的持水性、新鲜度、脂肪氧化程度、蛋白质热稳定性、凝胶特性、水分分布和微观结构的变化。结果显示,不同处理的解冻损失率和蒸煮损失率差异显著(P<0.05),超声微波解冻鱼肉的解冻损失率和蒸煮损失率最低,分别为1.52%和13.13%。低场核磁的结果显示超声微波解冻的样品中,细胞内水分向游离水迁移较少,说明超声微波解冻的鱼肉持水性较高。所有解冻样品的pH均与新鲜样品没有显著性差异(P>0.05),TVB-N值均低于15 mg/100 g,保持了较高的新鲜度。但超声远红外解冻、超声欧姆解冻、超声真空解冻和超声解冻的鱼肉TBARS值显著升高(P<0.05),脂肪氧化程度较高。超声微波解冻和超声远红外解冻的海鲈鱼具有较高的热稳定性和粘弹性,并且拥有更紧密光滑的微观结构。超声真空解冻的肌原纤维束发生轻微卷曲,超声欧姆解冻和超声解冻的纤维表面粗糙、结构疏松。其中,超声微波解冻是最优的解冻方式。     

Lipolytic and proteolytic properties of dry-cured boneless hams ripened in modified atmospheres

We studied proteolytic and lipolytic properties of dry-cured boneless ham (porcine quadriceps femoris) made with chilled (10°C, 48 h) or frozen/thawed meat (frozen at -20°C frozen for 90 days and followed by thawing at 10°C for 48 h) were determined. Dry-cured meats were stored in modified atmosphere packages (100% N(2) and a mixture of 75% N(2)+25% CO(2)) at 15°C with the intention of reducing ripening space. Results showed that dry-cured hams made with frozen/thawed raw meat had more salt, volatile fatty acids and free fatty acid content after salting and smoking. Whereas, samples prepared with chilled meats contained more nitrogenous compounds (water-soluble nitrogen, non-protein nitrogen, and free amino acids). Volatile and free fatty acid contents in all samples significantly increased with storage. Acetic acid was the predominant volatile fatty acid. To confirm lipolytic activity in dry-cured ham stored in modified atmospheres, we calculated the lipolytic coefficient. The lipolytic coefficients of all samples were positive values and significantly (P<0.05) increased with storage indicating lipolysis in samples were still active. Furthermore, nitrogenous compounds in dry-cured ham significantly (P<0.05) increased with storage indicating proteolysis in samples were not affected by modified atmosphere storage. Aerobic, anaerobic and lactic acid bacteria counts in dry-cured meats were stable to modified atmospheres storage for 20 weeks at 15°C. Flavor, texture and color score in sensory evaluation for dry-cured ham made with chilled meat were significantly higher than that made with frozen/thawed meat. All samples had high overall acceptance scores in sensory evaluation. Results in this study suggested that dry-cured boneless ham stored in modified atmospheres for 20 weeks at 15°C was another feasibility to ripen the meat without affecting lipolysis, proteolysis, microbiology and sensory quality.     

解冻和加工过程中冷冻猪肉保水性的研究

以冷冻猪4号肉为原料,研究解冻和加工过程中肉的来源、解冻方法、肉本身所含磷酸盐及加工过程中添加的磷酸盐对肉的保水性等指标的影响。结果表明:解冻过程中,解冻方法对猪肉的解冻汁液损失影响较大,肉流水解冻时汁液损失最小,保水性最好。当肉的来源不同时,汁液损失也不相同。肉本身所含磷酸盐对肉的解冻汁液损失影响较小。加工过程中添加不同浓度磷酸盐,对肉的保水性等指标影响显著(P<0.05)。当磷酸盐添加量≥0.4%时,肉的离心损失会显著下降(P<0.05)。在对肉保水性的影响方面,加工时添加的磷酸盐与解冻后肉本身所含磷酸盐及解冻方法之间存在交互作用。     

Physicochemical properties of thawed chicken breast as affected by microwave power levels

The main objective of this study was to determine the effect of microwave thawing at different power levels on the physicochemical properties of chicken breast. Each frozen chicken breast samples were thawed in microwave oven at microwave power levels of 125, 250, and 375W. To compare the effect of microwave thawing on meat quality, refrigerator thawing was used as a control. As the microwave power level increased, the thawing rate increased and temperature differences between the edge position and center position of the samples also increased. Treatment at a power level of 250 W resulted in a lower thawing loss and a higher moisture content, water holding capacity, and tenderness than the other treatments (p<0.05). However, there were no significantly differences of proximate composition excluding moisture content, pH, lightness, and yellowness. The use of excessive input energy during microwave thawing (higher microwave power level) damaged the physicochemical properties of the thawed chicken breast; therefore, the microwave power level of 250 W is the best thawing method on the frozen chicken breast to minimize the changes in meat quality in this study.     

解冻方式对冷冻秋刀鱼品质影响

目的为了探究适宜冷冻秋刀鱼的解冻方法,比较流水解冻、静水解冻、室温空气解冻和低温空气解冻对秋刀鱼鱼肉品质的影响。方法采用智能温度芯片系统对秋刀鱼解冻过程温度变化进行测定,以感官评分、解冻损失率、蒸煮损失率、硬度值、TVB-N值、肌原纤维蛋白含量、活性巯基含量、TBARS值为指标评定秋刀鱼解冻后的品质,并对肌肉组织结构进行观察。结果4种解冻方式将冻结秋刀鱼完全解冻耗时依次为低温空气解冻>室温空气解冻>静水解冻>流水解冻;低温空气解冻对应的解冻损失率和蒸煮损失率最低,而静水解冻和室温空气解冻之间解冻损失率和蒸煮损失率均无显著差异(P>0.05);低温空气解冻的硬度值显著高于其他解冻方式(P<0.05);4种解冻方式对应的TVB-N值和肌原纤维蛋白含量无显著差异(P>0.05),而低温空气解冻对应的活性巯基含量最低;流水解冻和静水解冻对应的TBARS值较高,低温空气解冻可有效延缓脂肪氧化;从肌肉组织结构看,秋刀鱼经低温空气解冻后肌肉纤维紧密、空隙小,而室温空气解冻造成秋刀鱼肌纤维变得松散并出现了轻微断裂现象。结论 从品质保持效果和经济效能考虑,低温空气解冻适宜作为实际生产中秋刀鱼的解冻方式。     

Characteristics of restructured beef steak with different proportions of walnut during frozen storage

Physicochemical (thawing loss, cooking loss, surface shrinkage, texture, colour and lipid oxidation) and sensory properties of restructured beef steak with different levels of added walnut (0%, 10% and 20%) were determined at various times during frozen storage up to 128 days. Cooking loss (CL), Kramer shear force (KSF) and binding strength (BS) of restructured beef decreased (P<0.05) as the proportion of walnut increased. Walnut enhanced (P<0.05) lightness and yellowness and reduced (P<0.05) redness. Frozen storage did not affect (P>0.05) CL, KSF and BS of restructured beef steak. Redness decreased (P<0.05) over storage for all samples. Lipid oxidation of restructured beef steak containing walnut was not a limiting factor for frozen stability of meat products. Frozen storage had no effect (P>0.05) on the sensory quality of restructured beef steak.     

Evaluation of the effects of different thawing methods on texture,colour and ascorbic acid retention of frozen hami melon (Cucumis melo var. saccharinus)

The effects of different thawing methods (room temperature thawing, running water thawing, microwave thawing at 300 W, 500 W, 700 W and high‐pressure thawing at 100 MPa, 150 MPa, 200 MPa) on quality (drip loss, texture, colour, ascorbic acid contents and sensory quality) of frozen hami melon were investigated. The results showed that different thawing treatments affected the quality of hami melon significantly (P < 0.05). Samples thawed by microwave at 500 W best preserved ascorbic acid for nearly half of fresh hami melon. Less drip loss, texture damage and discolouring were observed for the samples thawed by microwave at 700 W than other thawed samples; however, serious ascorbic acid loss was detected. High‐pressure‐thawed samples exhibited shorter thawing time but severe quality losses. The results suggested that microwave thawing at 500 W was an appropriate method to thaw frozen hami melon with the highest sensory score (6.7).