Influence of heat treatment on carnosine, anserine and free amino acid composition of beef broth and its role in flavour development

 In an attempt to determine the most important free amino acids (FAAs) in the development of the flavour of beef broths, the amino acid compositions of beef broths prepared at different temperatures and cooking times, with flavours of different intensities, were studied. From our data, broths obtained at temperatures above 75  °C and cooking times longer than 120 min had significantly lower levels of most of the FAAs studied (P<0.05). Statistical analysis of the sensorial and analytical data (principal component analysis, chi-square analysis) permitted the different FAAs to be grouped in relation to the flavour. There was a significant association between elevated levels of glutamic acid, asparagine (P<0.01), lysine and methionine (P<0.05) and the development of beef broth flavour. However, this was inversely related to levels of cysteine, proline, serine, M-histadine, tyrosine, valine, arginine and aspartic acid whereas reduced levels of β-alanine, asparagine, tyrosine, threonine, methionine, cysteine, leucine, isoleucine, tryptophan, glutamic acid, histidine, lysine and phenylalanine were associated with sapid properties not characteristic of beef broths (astringent, warmed-over flavours). A significant correlation (P<0.01) between sensory evaluation and carnosine and anserine levels was also observed. Received: 29 December 1998 / Revised version: 29 April 1999     

金针菇多糖复合重组肉脯的研制

本论文将金针菇多糖加入肉脯中,研究金针菇多糖、肥肉和白砂糖的添加量对肉脯总体接受程度的影响。通过单因素和响应面试验探究金针菇多糖鸡肉脯的最佳配方条件,并对成品的质构、色泽、氧化特性及体外抗氧化活性展开分析。结果表明,金针菇多糖鸡肉脯的最佳配方为:鸡胸肉850.00 g/kg、盐20.00 g/kg、复合磷酸盐3.00 g/kg、木瓜蛋白酶5.00 mL/kg、金针菇多糖3.00 g/kg、肥肉100.95 g/kg、白砂糖107.59 g/kg。添加金针菇多糖后,肉脯的硬度(13367.92 N)、咀嚼性(11048.72 N·cm)、亮度(L*值:36.10)和黄度(b*值:18.03)显著下降;产品的氧化程度得到有效控制,成品的羰基和TBARS值分别为0.50 nmol Trolox/mg pro和0.33 MDA mg/100 g,相比对照组分别降低了35.90%和82.20%。与此同时,产品还表现出良好的抗氧化活性(ABTS清除率:48.61 nmol Trolox/mg pro;DPPH清除率:62.85%;FRAP值:45.17nmol Trolox/mgpro)。本研究有助于提高传统鸡肉脯的附加值,同时可为功能性肉制品的开发提供理论依据。     

Changes in the physicochemical property and sensory quality of heat-processed beef flavour in the storage process

This study aimed to investigate changes in the quality of heat-processed beef flavour (HPBF) during 168-day storage period at 4, 20 and 50 °C through evaluating 10 physicochemical indexes and sensory profiles. The sensory score of HPBF reduced dramatically at 50 °C compared with those at other temperatures. The correlation analysis indicated that among the 10 physicochemical indexes, oxidation–reduction potential (ORP), which is positively correlated to lipid oxidation, possessed the strongest association with the total sensory score of HPBF. The kinetic analysis showed that the increasing rate of ORP during the first 50-day period at 50 °C was more than 10 times larger than those at 4 and 20 °C. These results suggested that lipid oxidation played a major role in affecting the quality of HPBF, especially during the early storage period. Reducing lipid oxidation via for instance maintaining a relatively low storage temperature should be given better attention for obtaining high-quality HPBF.