【作者】 周亚平；

【导师】 戴洪义；

【作者基本信息】 莱阳农学院 ， 果树学， 2006， 硕士

【摘要】 本研究以“特拉蒙”ד富士”、“特拉蒙”ד新红星”苹果杂交品系(95-32、95-33、95-51、95-70、95-124、95-153)和“鲁加4号”(95-76)的浓缩果汁为试材,研究了不同基因型苹果果实加工指标;不同基因型苹果浓缩汁贮藏过程中A420值、总色差值、5-羟甲基糠醛(5-HMF)、还原糖及氨基酸含量的变化;贮藏温度、pH值、糖度、果实成熟度对“鲁加4号”浓缩汁非酶褐变的影响。在柠檬酸-磷酸缓冲液(pH=3.2)和浓缩汁中进行了氨基酸与还原糖美拉德反应模拟试验。主要研究结果如下:1.不同基因型苹果果实加工指标存在较大差异。95-32,95-70果实成熟期较晚,果实可溶性固形物含量较高,多酚氧化酶活性、△A420值和△T625值较低;95-51,95-153果实成熟期较早,果实可溶性固形物含量较低,多酚氧化酶活性、△A420值和△T 625值较高。果实成熟期对果实可溶性固形物含量有显著影响,早熟果实的浓缩汁易褐变。果汁加工过程中的酶促褐变对浓缩汁贮藏过程中的非酶褐变有显著影响。2.随着贮藏时间的增加,供试品系苹果浓缩汁总色差值不断增加,95-32,95-70浓缩汁总色差值的增加值最小,95-51,95-153浓缩汁总色差值的增加值最大。贮藏过程中,95-32,95-70浓缩汁5-HMF含量先上升后下降,再上升;95-33,95-124浓缩汁5-HMF含量是先上升后下降;而95-51,95-153浓缩汁5-HMF含量是先下降后上升。不同基因型苹果浓缩汁5-HMF含量出现的峰值差异显著,95-33,95-124浓缩汁5-HMF含量的峰值最高,95-32,95-70浓缩汁5-HMF含量的峰值最低。不同基因型苹果浓缩汁还原糖含量的变化趋势差异不明显(95-32除外),还原糖含量成波浪式变化,即先上升后下降,然后上升再下降。贮藏过程中,苹果浓缩汁中赖氨酸、苯丙氨酸、亮氨酸、异亮氨酸、蛋氨酸、苏氨酸含量总体上呈下降趋势。3温度对苹果浓缩汁贮藏过程中非酶褐变影响极显著,贮藏温度越高,浓缩汁的非酶褐变越严重;糖度对浓缩汁贮藏过程中非酶褐变影响显著,在55oBrix~75oBrix范围内,浓缩汁糖度越高,非酶褐变越严重;pH值和果实成熟度对浓缩汁非酶褐变也有显著性影响,浓缩汁贮藏1~2周期间,pH值与A420值呈正相关,贮藏3~4周期间,pH值与A420值呈负相关;不同采收期苹果果实出汁率、可溶性固形物含量、多酚含量、浓缩汁酸含量不同。果实成熟时采收制得的浓缩汁非酶褐变发生较轻。4.用氨基酸和还原糖分别在柠檬酸-磷酸缓冲液(pH3.2)与苹果浓缩汁中进行美拉德反应模拟试验表明,在苹果浓缩汁中进行的模拟试验,氨基酸与还原糖的反应活性分别比柠檬酸-磷酸缓冲液(pH3.2)条件下的高。利用苹果浓缩汁体系的模拟试验能更好的推测苹果浓缩汁中氨基酸与还原糖的实际反应活性。在两个反应体系中,氨基酸中以赖氨酸的反应活性最高。更多还原

【Abstract】 Studies were carried out on processing indexes of fruits, the changes of A420, color aberration values,5-hydroxymethyl furfuraldehyde(5-HMF), reductive sugars and amino acids contents of apple juiceconcentrates of hybrids(95-32、95-33、95-51、95-70、95-124、95-153) during the course of storage,and influences of temperature, pH, sugar(soluble solid substance) content and degree of fruit maturation onnon-enzymatic browning of apple juice concentrate of Lujia4 (95-76). All the hybrid apple trees werederived from two crosses (Telamon×Starkrimson, Telamon×Fuji). Maillard reactions caused by amino acidsand reductive sugars were simulated in citric acid-phosphate buffer(pH3.2)and in apple juice concentraterespectively. The main results were as follows:1. There were great differences among processing indexes of different genotypes in apple. The timesof fruit maturation of strains (95-32, 95-70 ) were late, and sugar (soluble solid substance) contents of fruitswere high, and PPO activities, △ A420 and △ T625 values were low;Times of fruit maturation of strains(95-51, 95-153 ) were early, and sugar (soluble solid substance) contents of fruits were low, and PPOactivities, △ A420 and △ T625 values were high.The time of fruit maturation had an obvious effect on sugar (soluble solid substance) content of fruit.Early ripening fruits tended to be browning easily. Enzymatic browning in juice processing had asignificant effect on non-enzymatic browning of apple juice concentrates during the course of storage.2. Color aberration values of different genotype apple juice concentrates were increased with the lengthof duration of storage, but those of strains (95-32, 95-70 )apple juice concentrates rose slowly, and those ofstrains (95-51, 95-153) apple juice concentrates rose quickly during the course of storage. 5-HMF contentsof strains (95-32, 95-70 )apple juice concentrates rose first, then descended, and rose again, and those ofstrains (95-33, 95-124 )apple juice concentrates rose first, then descended, but those of strains (95-51,95-153 )apple juice concentrates descended first, then rose;Peak values of 5-HMF contents were quitedifferent among different genotype apple juice concentrates. The highest values were found in strains(95-33, 95-124) apple juice concentrates, and the lowest values were found in strains (95-32, 95-70) applejuice concentrates. Change trends of reductive sugars contents were mere less the same expect for 95-32,and reductive sugars contents rose first, then descended, rose and descended again. Lysine, phenylalanine,leucine, isoleucine, methionine and threonine contents of apple juice concentrates had declined during thecourse of storage.3.Temperature had a great effect on non-enzymatic browning of apple juice concentrate during thecourse of storage, and the higher temperature was , the more evident non-enzymatic browning of applejuice concentrate was;Sugar content also had a great effect on non-enzymatic browning of apple juiceconcentrate, and the higher sugar content of apple juice concentrate was, the more evident non-enzymaticbrowning of apple juice concentrate was;pH and fruit maturation degree significantly affectednon-enzymatic browning of apple juice concentrate as well, and pH was positively correlated with A420within 2 weeks during the course of storage at 25oC, whereas pH was negatively associated with A420 after2 weeks storage. Juice output ratio, soluble solid substance content, polyphenol content of fruit, and acidcontent of apple juice concentrate varied with degree of fruit maturation. Light non-enzymatic browningapple juice concentrate was found with fully matured fruit.4.In the simulations of maillard reation activities of both amino acids and reductive sugars in applejuice concentrate were higher than those in citric acid-phosphate buffer(pH3.2). Simulation experiment inapple juice concentrate seemed to be more suitful for detecting the reality between amino acids andreductive sugars reation than that in citric acid-phosphate buffer(pH3.2). Reation activity of lysine inamino acids was the highest in amino acids tested.更多还原