不同冷却方式对熟制包子品质的影响

包子熟制之后需要冷却然后才能进行包装贮藏,为找到最适合熟制包子的冷却方式,文中通过对产品进行自然冷却、鼓风冷却、真空冷却和混合冷却4种不同的处理,比较其在同一温度下贮藏不同时间的品质变化。结果表明:不同冷却方式对产品保质期有不同影响(P<0.05),混合冷却方式具有取代常规冷却和真空冷却方式的可行性。混合冷却的质量损失明显低于真空冷却而冷却速率显著快于常规冷却方式;在色泽方面混合冷却可以改善真空冷却的颜色较暗这一缺点;在硬度与电子鼻分析方面混合冷却与常规冷却相比有较明显差异(P<0.05),但相对于真空冷却已有提高,在黏聚性、黏性、咀嚼性等方面混合冷却与常规冷却没有显著差异(P>0.05);感官评分的可接受性明显优于真空冷却。在化学指标测定方面:混合冷却与真空冷却对pH值变化的影响较小(P>0.05)并且可以降低包子皮的老化程度;混合冷却与真空冷却均可以显著延缓微生物污染和脂肪氧化程度,从而达到延长食品货架期的目的。     

煎、炸、烤对横山羊肉食用品质的影响

以横山羊肉为研究对象,通过调控处理时间和温度,进行煎、炸、烤三种工艺处理,采用质构仪测定肉样的全质构和剪切力,用测色仪测定肉色,进而对肉样的食用品质进行综合评价。结果表明:对于煎制处理,2min和3min处理的肉样硬度、咀嚼性及回复性显著小于4min(P0.05);2min和3min处理的肉样剪切力显著小于4min(P0.05);肉样L*值随处理时间的延长逐渐减小(P0.05),2 min和3 min处理的肉样a*值小于4min(P0.05),而b*、c*及h°值大于4min(P0.05)。对于炸制处理,3 min处理的肉样硬度和内聚性显著小于4 min和5 min(P0.05),咀嚼性、弹性及回复性显著小于5min(P0.05);3 min处理的肉样剪切力显著小于4min和5min(P0.05);3min处理的肉样a*值小于5min(P0.05),其他肉色指标对不同的处理时间差异不显著(P0.05)。对于烤制处理,160℃处理的肉样硬度、内聚性和回复性小于180℃(P0.05),弹性小于200℃(P0.05);160℃处理的肉样剪切力显著小于200℃(P0.05);160℃处理的肉样L*值小于180℃和200℃(P0.05),a*和c*值小于200℃(P0.05),h°值大于200℃(P0.05),b*值对不同的烤制温度无显著差异(P0.05)。综合分析表明:煎、炸、烤三种高温处理对横山羊肉食用品质有较大影响,肉样在226~228℃的温度下煎制处理3 min和炸制处理3min、在160℃的温度下烤制处理40min,均具有较高的食用品质。该研究结果对于人们选择合理的羊肉高温处理方式及工艺条件具有一定的指导意义。     

冷却对熟粽子品质的影响

粽子在蒸煮后需冷却。为了寻找合适的冷却方法,通过真空冷却、冷风冷却、自然冷却3种方式处理煮后的3种速冻粽子,测定这些粽子的品质差异。结果表明:与常规冷却方式相比较,真空冷却速率高(P0.05),冷却损失较高(P0.05)。质构分析表明:真空冷却产品硬度较大(P0.05),而黏着性、弹性、内聚性、胶黏性、咀嚼性和回复性方面没有显著差异(P0.05)。感官分析表明:真空冷却的产品口感虽然不及常规冷却的产品,但在可接受的范围。化学指标分析表明,真空冷却能显著降低菌落总数。电子鼻分析结果表明:豆沙粽子和肉粽子真空冷却与常规冷却的产品挥发性气味显著不同,而对白粽子的影响不显著。真空冷却是一种快速、安全的冷却方法。     

酱卤鸡肉真空冷却的可行性评估研究

研究了真空冷却、浸液真空冷却、自然冷却和鼓风冷却,得到冷却方式对冷却速率、冷却损失、品质变化及后期贮藏阶段微生物的影响,进一步对真空冷却和浸液真空冷却可行性评估。普通真空冷却质量损失过多,对产品产生一些负面影响。实验尝试对样品进行浸液真空冷却,避免了水分的大量损失,其冷却时间明显小于自然冷却和鼓风冷却(p0.05)。对品质的影响:不同冷却方式之间,剪切力、TPA、色度值均存在差异。真空冷却样品的剪切力、硬度、咀嚼性要明显大于其他冷却(p0.05),弹性较差,真空冷却形成的多孔结构对后期储藏阶段脂肪氧化有促进作用。真空冷却的样品微生物数量显著低于自然冷却和鼓风冷却,对产品的保藏有利。综合评估,浸液真空冷却要优于其他冷却方式。     

真空冷却-浸入式真空冷却对白煮鸡腿品质影响

以白煮鸡腿为研究对象,使用真空冷却-浸入式真空冷却、真空冷却、浸入式真空冷却、传统的冷却方法风冷、水冷方法比较产品品质和冷却效果。比较结果表明白煮鸡腿的中心温度从72℃降至10℃用真空冷却-浸入式真空冷却方法降温速率最快,并且弹性显著(p0.05)大于其他冷却方式,a*、剪切力、硬度、胶着性和咀嚼性与水冷无显著性(p0.05)的差别,各冷却方式的白煮鸡腿pH在一周的贮藏期内无显著性差别(p0.05)。真空冷却-浸入式真空冷却方法的冷却速率快,且最终冷却产品的品质也较好。     

3种传统中式高温烹饪工艺对牛肉食用品质的影响

为研究烤、炸、煎3种传统中式烹饪工艺对牛肉食用品质的影响,采用分光测色仪、质构仪测定牛肉制品的色泽、剪切力和硬度、咀嚼性、弹性、内聚性、回复性等指标,从而综合评定其食用品质。结果表明:3种烹饪工艺对牛肉的食用品质影响显著(P0.05)。对于烤制工艺,牛肉的L*与c*值随烹饪时间的延长显著减小(P0.05);160℃与180℃比200℃处理组的牛肉h°值大(P0.05);160℃与200℃烤制的牛肉b*值小于180℃处理的b*值(P0.05)。对于剪切力,160℃与180℃处理组显著小于200℃处理组(P0.05)。烹饪温度对牛肉的硬度、咀嚼性、回复性有显著影响(P0.05);160℃与180℃处理组的牛肉弹性、内聚性显著小于200℃的处理结果(P0.05)。对于炸制工艺,牛肉L*、b*值随烹饪时间的延长逐渐减小,c*与h°值逐渐增大;3min处理组的牛肉L*与c*值显著不同4 min与5 min的处理结果;3 min与4 min处理组的牛肉b*、h°值显著不同于5 min的处理结果(P0.05)。对于剪切力,3 min处理组显著小于5 min处理组(P0.05)。4 min与5min处理组比3 min处理组的牛肉硬度、咀嚼性大(P0.05);4 min处理组的牛肉弹性、内聚性、回复性显著小于3 min与5 min的处理结果。对于煎制工艺,牛肉a*值随烹饪时间的延长逐渐增大,其他肉色指标逐渐减小;2min与4 min处理组间的牛肉L*、a*、c*值差异性显著(P0.05);2 min与3 min处理组比4 min处理组的牛肉h°值大(P0.05)。对于剪切力,2 min与3 min处理组显著小于4 min处理组(P0.05)。2 min与3 min处理组比4 min处理组的牛肉咀嚼性小(P0.05);2 min煎制的牛肉弹性显著小于3 min与4 min的处理结果(P0.05)。综合分析发现,牛肉在160℃下烤制40 min以及在226~228℃下炸制3 min、煎制2~3 min均具有较高的食用品质。     

宰后不同冷却方式对羊肉品质的影响

为了建立适宜的宰后羊肉冷却程序,采用不同冷却方式(常规冷却,0~4℃放置96 h);延迟冷却,(15±0.5)℃先冷却8 h,然后在0~4℃条件下冷却至96 h;高温冷却,(25±0.5)℃冷却2h,然后放置在0~4℃条件下继续冷却至96 h)对宰后羊肉进行冷却处理,研究不同冷却方式对羊肉品质的影响。研究结果表明:延迟冷却和高温冷却显著增加了羊肉的蒸煮损失率,降低了羊肉的剪切力值,提高了羊肉嫩度,缩短了羊肉的成熟时间(P<0.05);同时提高了羊肉的L*值(P<0.05),增加了a*值(P<0.05),使羊肉的色泽鲜红;此外高温冷却和延迟冷却提高了羊肉的羰基含量(P<0.05),降低了巯基含量(P<0.05),温度越高,羊肉蛋白的氧化程度越大;而且高温冷却的菌落总数显著高于常规冷却和延迟冷却(P<0.05),存在腐败的风险。试验结果证实延迟冷却和高温冷却对羊肉品质的改善均具有积极作用,但考虑微生物和蛋白氧化的因素,延迟冷却更适宜作为宰后羊肉冷却程序。     

烟熏时间对培根杂环胺含量及产品品质的影响

本实验以培根为对象,研究烟熏时间对培根品质和杂环胺含量的影响。将腌制好的猪肋腹肉放入烟熏炉中,在45～50℃下分别烟熏0、0.5、1.0、1.5、2.0、2.5、3.0 h,测定烟熏过程中杂环芳香胺(heterocyclic aromatic amines,HAAs)含量和产品品质等指标的变化情况。结果表明,较长的烟熏时间会导致产品中非极性HAAs含量显著增大(P0.05);而极性HAAs先显著增大(P0.05)后减小,且在烟熏1 h时达到最大值。色差结果表明,亮度(L*值)先显著减小后显著增大(P0.05),而红度(a*值)和黄度(b*值)先显著增大后显著减小(P0.05)。此外,产品的水分含量和水分活度均随着烟熏时间的延长而显著降低(P0.05),而pH值、羰基含量和硫代巴比妥酸反应产物值均显著增大(P0.05)。低场核磁共振结果显示,随着烟熏时间的延长T_(2b)弛豫时间无显著差异(P0.05),而T_(21)和T_(22)弛豫时间显著降低(P0.05),表明烟熏导致了产品中水分分布的变化。总之,烟熏时间能显著影响培根HAAs含量及食用品质。     

不同冷却方法对馒头贮藏过程品质的影响

通过对馒头采用自然冷却、冷风冷却和真空冷却3种冷却方法,并在4℃的条件下对产品进行贮藏,研究面食品质的变化。结果表明,相对于其他冷却方法,真空冷却将馒头从85℃冷却至20℃所用时间最短,仅为900s,冷却速率高,产品质量损失大,失重率可达到1.683%;冷却后产品硬度、黏性、咀嚼性较大,但粘结性和回弹性方面3种冷却方式没有明显差异;亮度L*偏小,红度a*偏大,黄度b*差异不明显。真空冷却能够有效抑制微生物生长,从而延长食品的保存期。     

不同冷却方式对低温熟制猪肉品质的影响

以低温（80 ℃）熟制的猪肉为研究对象,采用冷藏冷却（4 ℃）、冷冻冷却（?18 ℃）和真空冷藏冷却（4 ℃）3种方式将其从80 ℃冷却至10 ℃,研究冷却速率、质量损失率、质构特性、色泽以及硫代巴比妥酸值（TBA）等品质变化,并研究其在4 ℃下贮藏期间的TBA值及气味等品质变化情况。结果表明:真空冷藏冷却和冷冻冷却的冷却速率显著高于冷藏冷却（P<0.05）;冷藏冷却质量损失最大（6.67%）（P<0.05）,冷冻冷却质量损失最少（4.47%）;真空冷藏冷却具有最小的L*值,a*值和最大的b*值（P<0.05）;冷藏冷却处理具有最大的硬度值（13647.14±51.47 g）（P<0.05）;真空冷藏冷却的样品气味较其他两组处理的气味差别大;在冷却结束和贮藏过程中冷藏冷却处理组的TBA值均显著高于其他两组（P<0.05）;随着贮藏时间的增加,3组样品的气味差异变大。冷冻冷却和真空冷藏冷却均能生产较好品质的低温猪肉制品,且具有较好的贮藏品质。     

Effect of rapid and conventional cooling methods on the quality of cooked ham joints

Three cooling regimes, vacuum (VC), blast (BC) and slow cooling (SC), were compared for their effect on cooling rate, weight loss and quality of large cooked ham joints. Vacuum cooling reduced the cooling rate (70-4°C) significantly (P<0.05) in comparison to the other methods; mean cooling times for cooked hams (5-6 kg) were 1.9 h for VC, 11.7 for BC and 14.3 for SC. However, VC gave an increased chill loss (P<0.05) of ca. 11% compared to ca. 4% for the other methods due to evaporative moisture loss. Sensory panels found that VC hams were tougher and less juicy (P<0.05). Shear force measurements and texture profile analysis also showed the vacuum cooling to have a toughening effect on the cooked ham. While vacuum cooling had an adverse effect on quality and yield, it was the only one that conformed to recent safety guidelines for cooked meat joints of a reduction in temperature to 5°C inside 10 h. The cooling conditions used do not reproduce full-scale industrial practice, however, the effects found serve as an indicator of the potential benefits and drawbacks of vacuum cooling for cooked meat joints.     

不同干燥方式下鮰鱼片的干燥特性及风味变化

本文以鮰鱼为原料,研究了不同干燥方式对鮰鱼干燥特性的影响,并利用气相离子迁移色谱(GasChromatographyIon MobilitySpectrometry,GC-IMS)、电子鼻、电子舌以及氨基酸自动分析仪等技术,对不同干燥方式对鮰鱼片风味进行了分析。结果表明,真空冷冻干燥的鮰鱼片收缩率最小,为5.44%,显著低于其他三种干燥方式(p<0.05),且其复水速率最快,用时最短;热风干燥的鮰鱼片硬度最大,达1929.70 g,与其他三种干燥方式之间有显著性的差异(p<0.05);真空干燥使得鮰鱼片的L*值为最小,a*值和b*值最大,使鮰鱼片呈现焦糖色,而真空冷冻干燥的L*值最高,a*值和b*值最低,使鮰鱼片呈现白色;热风干燥和微波干燥的鮰鱼片气味比较相似,热风干燥和真空干燥处理的鮰鱼片的滋味比较相似,而真空冷冻干燥气味和滋味都区别于其他三种干燥方式;热风干燥和真空冷冻干燥的甜味氨基酸含量分别比苦味氨基酸含量高51.97 mg/g和67.66 mg/g;微波干燥和真空干燥的苦味氨基酸含量分别比甜味氨基酸含量高3.56 mg/g和6.11 mg/g。因此,真空冷冻干燥对鮰鱼片的干燥特性影响最小,且风味有区别于其他三种干燥方式。     

The effect of injection level and cooling method on the quality of cooked ham joints

The effect of cooling method and injection level on cooling rate, weight loss and quality of large cooked ham joints was investigated. Two cooling methods, vacuum (VC) and conventional (CC) and two injection levels (20 and 30%) were examined. VC reduced the cooling rate (70?°C to 4?°C) significantly in comparison to the CC (2.5 h vs. 12.5 h). Under these test conditions, VC conformed to recent safety guidelines for cooked meat joints of a reduction in temperature to 5?°C inside 10 h in comparison to CC. The injection rate had no affect on the cooling rate. Increased weight loss due to vacuum cooling was off-set by increasing the level of brine injection in pork legs from 20 to 30% and getting a yield after VC similar to that for CC hams injected at 20%. Injection rate had no affect on the sensory attributes but cooling method did; VC hams were slightly tougher (P<0.05) and drier (P<0.01) than CC hams. While VC hams injected to a 30% rate were less tender and juicy than CC hams injected at a 20% rate, as indicated by sensory scores and some instrumental texture parameters, they were similar in shear value and in overall acceptability.     

Effect of cooking bag and netting packaging on the quality of pork ham during water cooking

As a preliminary test for combining water cooking with vacuum cooling in soup of pork ham, three package treatments were designed to study the effect of cooking bag and netting on the quality of water cooked ham, i.e. ham cooked with a cooking bag and without a cooking bag (single netting and double netting). For treatments without a cooking bag, the results indicated that there was no significant superiority of ham cooked with double netting compared with ham cooked with single netting on the processing efficiency and quality characteristics. Although the hams cooked with a bag performed better in some chemical retentions and pigment, the water contents were significantly lower than those hams cooked in single netting (P<0.05), and there was a higher shrinkage tendency compared with the hams cooked without a bag. For the processing characteristics and texture properties of pork ham, there were no significant differences observed among the treatments with and without a cooking bag in terms of the combined effect of cooking and cooling (P>0.05). By considering the safety, convenience, cost, and the recovery effect on the quality changes of ham during vacuum cooling in soup, cooking with single netting is a better choice for future research.     

Evaluation of Bubbling Vacuum Cooling for the Small-Size Cooked Pork

Vacuum cooling has notable advantages including fast cooling rate, cleanness, and high energy efficiency. However, the weight loss of food after being vacuum cooled was unsatisfactory, especially for meat products. Immersion vacuum cooling can significantly reduce the weight loss of food compared with traditional vacuum cooling procedures, but the cooling rate is unacceptable. To overcome this problem, here, a novel vacuum cooler, bubbling vacuum cooler, was designed and evaluated for the small-size cubic cooked pork with a side length of 1.5 cm from about 60 to 4 °C. Experimental results indicated that bubbling vacuum cooling can reduce the weight loss (about ??2.3%) of food compared to both vacuum cooling (about 12.4%) and immersion vacuum cooling (about 0.5%) (P?<?0.05). Further, bubbling vacuum cooling can cool the sample with a slightly more rapid cooling rate (0.10 °C/s) contrasted with immersion vacuum cooling (0.07 °C/s) (P?>?0.05). For the chromatism value of sample, no significant difference was found between immersion vacuum cooling and bubbling vacuum cooling (P?>?0.05). The textural property of sample cooled by bubbling vacuum cooling was close to (for hardness, elasticity, chewiness, and shear force, P?>?0.05) and better (for cohesiveness, P?<?0.05) than that of immersion vacuum cooling. Thus, our experiment demonstrated that cooked pork cooled by bubbling vacuum cooling has a lower weight loss rate and a more rapid cooling rate than that of immersion cooling.     

蒸烤模式对南美白对虾食用品质的影响

以南美白对虾为研究对象,以色差值、质构品质、游离氨基酸含量及感官评分为指标,通过色彩色差计、物性测试仪、氨基酸专用高效液相色谱仪以及感官评价法考察不同蒸烤模式（纯蒸、纯烤、先蒸后烤、先烤后蒸、蒸烤交替）对虾肉食用品质的影响。结果表明：先烤后蒸模式下虾皮和虾肉的L*值显著低于其他4 种模式（P＜0.05）;纯烤模式下虾的硬度和咀嚼性均显著高于其他4 种加热模式（P＜0.05）;游离氨基酸含量分析结果显示,纯蒸模式下虾的游离氨基酸总量最多,蒸烤交替模式下甜味氨基酸比例最高、苦味氨基酸比例最低。最后综合感官评定结果得出,在南美白对虾的不同蒸烤模式中,纯蒸和蒸烤交替模式优于其他3 种加热模式。     

真空冷却技术在熟肉制品工业化生产中的应用研究

真空冷却技术是依据较高温度的含水物料在密封环境中真空的条件下通过水分迅速蒸发使物料自身得到迅速降温冷却的原理,这项快速蒸发冷却技术过去仅局限应用在蔬菜和鲜花的冷却保鲜等领域中,本课题研究真空冷却技术应用在熟肉制品生产的冷却工艺中,实验结果表明:相同的熟肉产品从95℃冷却到20℃,真空冷却比传统自然冷却速度快20倍以上,该技术可有效防止微生物在产品中的污染和增殖,提高产品的质量和安全性,延长产品货架期。研究同时就真空冷却技术对产品失水率的影响作了探讨。     

Vacuum cooling of meat products: current state-of-the-art research advances

Vacuum cooling (VC) is commonly applied for cooling of several foodstuffs, to provide exceptionally rapid cooling rates with low energy consumption and resulting in high-quality food products. However, for products such as meat and cooked meat products, the higher cooling loss of vacuum cooling compared with established methods still means lower yields, and important meat quality parameters can be negatively affected. Substantial efforts during the past ten years have aimed to improve the technology in order to offer the meat industry, especially the cooked meat industry, optimized production in terms of safety regulations and guidelines, as well as meat quality. This review presents and discusses recent VC developments directed to the cooked meat industry. The principles of VC, and the basis for improvements of this technology, are firstly discussed; future prospects for research and development in this area are later explored, particularly in relation to cooling of cooked meat and meat products.     

真空冷却与常规冷却方式对白煮牛肉品质影响的比较

本实验研究了真空冷却方式与冷风冷却,自然冷却方式对白煮牛肉品质的影响。样品中心温度从80℃冷却到10℃以下,与冷风冷却(120min)室温冷却(240min)相比较,真空冷却(24min)冷却速率较高。与常规冷却方式相比较,真空冷却的冷却损失较高,剪切力较大,硬度较大,弹性较低,色泽较差。感观分析表明,真空冷却样品总体可接受性不及常规冷却样品。微生物检测表明,真空冷却能显著降低菌落总数,减少细菌增殖,保证样品的卫生质量。