摘要
梨是我国第三大水果,2008年产量达1367万吨,约为世界总产量的三分之二,居世界第一位。但是我国梨果加工量很少,不到总产量的10%,致使采收期大量梨果涌入市场,销路不畅,甚至造成极大浪费。研究梨果的加工特性,解决产品加工过程中出现的问题,可以有效缓解梨果采后鲜销和贮藏压力,提高果农收入,从而提高梨果产业效益和推动产业发展。本文以鸭梨、砀山酥、黄金、花盖、南果、五九香等23个代表性梨品种为原料,研究了其制汁特性,筛选出适于制汁的3个品种,总结提出了梨果制汁适应性的评价方法；同时研究了秋子梨后熟程度对制汁特性的影响,以及梨果汁酶促褐变的机理、非酶褐变的控制方法,以期为梨果加工品质提高提供技术支撑。
1.梨制汁品种的筛选应从理化指标(可溶性固形物、糖、酸)、出汁率、褐变度(酚含量、PPO活性、L值、OD420nm值)3个方面综合考虑。供试品种中秋白、黄金、安梨为最佳的制汁品种。梨果实的果皮中酚类物质含量最高,果心次之,果肉中含量最低,果皮中酚的含量与果汁褐变度有显著的相关性。多数梨品种果皮中的PPO活性很高,果肉中的PPO活性很低,所以定位高档的果汁加工时可考虑去皮以减轻褐变。
2.以口味淡薄的鸭梨和砀山酥梨为主要原料进行混合梨汁试验,正交设计确定最优组合：Ⅰ：砀山酥梨汁50ml,安梨汁25ml,锦香梨汁30ml混合；Ⅱ：鸭梨汁50ml,花盖梨汁15ml,尖把儿梨汁20ml混合。
3.秋子梨等软肉梨制汁时要先经过后熟。秋子梨的硬度在2.5～4.0kg／0.5cm2时,硬度适当,此时的出汁率较高,单宁含量低,褐变程度也较低,此时适宜制汁。
4.黄金梨汁和秋白梨汁贮存过程的非酶促褐变中,氨基酸、还原糖和总酚的含量变化与褐变指数(OD420nm)极显著负相关,与L值极显著正相关。梨汁贮藏过程中非酶褐变发生的类型主要是美拉德反应和酚类物质的氧化。低温贮藏能有效的抑制非酶促褐变反应的发生。
5.黄金梨汁和秋白梨汁贮存中褐变指数(OD420nm)随温度和时间的增加而上升。20℃下贮存,黄金梨汁的色值变化符合两阶段复合型,秋白梨汁符合抛物线型。0℃下贮存时,黄金梨汁和秋白梨汁符合1级模型。黄金梨汁贮藏时褐变反应的活化能是Ea=12.13kcal／mol,秋白梨汁的活化能是Ea=10.73kcal／mol,黄金梨汁比秋白梨汁更容易发生褐变。
6.南果梨是秋子梨中的优良品种,但制汁时褐变严重,利用抗褐变剂可以有效的抑制其酶促褐变反应的发生。相同浓度下,所选5种抗褐变剂的抗褐变能力：Na2SO3>Vc>L-半胱氨酸>柠檬酸>CaCl2.对PPO活性的抑制能力：L-半胱氨酸>Na2SO3>柠檬酸>Vc>CaCl2。抗褐变剂混合使用效果更佳,建议用量：抗坏血酸0.046%、L-半胱氨酸0.037%、柠檬酸0.0401%的配比。
Pear is the third largest output fruits in China,13670 tons was harvested in 2008, which is almost 2/3 of all the world harvested, ranking the first. While, the amount of pear being processed is less than 10% of the total.In the harvest period, there are so many pears in the market that many can't be sold and rot at last. Studying the pears' processing characters deeply, solving the problems occurred during processing and storage are effective ways to improve benefits and promote development of the industry. 23 pear varieties such as Yali、TsuLi、Whangkeumbae, Huagai, Nanguo were referred in the experiments, which offered academic guidance for pear industry by studying the pears' juice-processing characters, screening juicing suitable varieties and summarizing methods to select juicing variety. Effects of ripening degree on juicing performance were also studied, and then mechanism of nonenzymatic browning and the control of enzymatic browning were discussed in order to provide technical support. The experiments investigation indicates:
1. Physical and chemical indicators (total sugar, reducing sugar, titratable acid, soluble solid content, juice yield),degree of browning (total phenolics, PPO activity, OD420nm, L) and sensory evaluation (appearance, taste, smell) should be considered before identify a juicing variety, which should be good in taste, high in juice yield, low in browning degree. Jinxiang, Whangkeumbae, Anli were the best varieties of all the 23. Total phnolics are richest in fruit skin, and then in fruit core, poorest in fruit flesh, and total phenolics of pear skin correlated significantly with colour value. Most varieties' PPO activity in fruit skin is high, while, in flesh is relatively low.
2. Juice of Yali and taste less flavor, mix them with palate fullness juice, orthogonal experimental design to get two best recipes:Ⅰ:TsuLi-juice 50ml, Anli-juice 25ml, jinxiang-juice 30ml;Ⅱ:Yali-juice 50ml, Huagai-juice 15ml, jianbaer-juice20ml.
3. For Pyrus ussuriensis Maxim, ripen firstly before juice until the firmness is suitable, the juice yield is high, the tannic is less, and the browning is light. When the firmness is 2.5～4.0kg/0.5cm2 can meet the demands above.
4. In the nonenzymatic of Whangkeumbae juice and Qiubai juice during storage, the concentration of total amimo acid、sugar and total phenolics decreased, and they are correlated negatively with OD420、positively with L value. Maillaid reaction and phonelics oxidation were the main factor of nonenzymatic browning. Storage in low temperature can inhibit nonenzymatic browning effectively.
5. OD420 of Whangkeumbae juice and Qiubai juice increased with both time and temperature. Storaged in 20℃, Whangkeumbae juice fits two stages combined reaction kinetic, and Qiubai juice fits parabola kinetic. While storaged in 0℃, both fit zero order. Browning activation energies of Whangkeumbae juice and Qiubai juice are 12.13kcal/mol and 10.73 respectively, Whangkeumbae juice browns easier than Qiubai juice.
6. Antibrowning agents can inhibit enzymatic effectively during pear juice is being processed. With the same concentration, the inhibition ability of studied antibrowning agents was: Na2SO3>Vc>L-Cysteine>Citric acid>CaCl2。The PPO inhibition ability was:L-cysteine> Na2SO3> Citric acid>Vc> CaCl2。Inhibition ability strengthen significantly when mixed, according response surface methodology, the optimum combination was determined as Vc 0.046%、L-Cysteine 0.037%, Citric acid 0.0401%.
引文
1. 蔡金星,李秀锦,刘秀凤.不同品种梨多酚氧化酶特性及其抑制剂的研究.河北农业师范学院院报,1999,13(1),55～58.
2. 曹建康,姜微波,赵玉梅.果蔬采后生理生化试验指导.北京：中国轻工业出版社.2007,103～105.
3. 曹玉芬,孙希生,姜淑苓,张微,王文辉,谭兴伟,等.中国果树,2003,20(6),450～454.
4. 陈清泉.果汁非酶促褐变及其抑制方法(上).食品工业,1992,1,45～51.
5. 陈秀芳,王坤范.桃果实褐变中揭变因子变化规律的研究.园艺学报,1995,22(3)：230～234.
6. 陈学平.果蔬产品加工工艺学.北京：中国农业出版社.1995,38～39,107～133.
7. 程建军,马莺,杨咏丽.苹果梨中多酚氧化酶酶学特性的研究.园艺学报,2002,29(3),261
8. 程建军,王震新,于静海.苹果梨和鸭梨酶促褐变机理的研究.食品科学,2002,21(2),71～74.
9. 慈志娟.杏果实酶促褐变控制与制汁适应性评价体系的研究[硕士学位论文].山东农业大学,2003.
10.丁筑红,王淮生.皂土、壳聚糖澄清剂对发酵酒澄清作用的研究．中国酿造,2005,(11),11～15.
11.方成泉,林盛华,李连文,马志强.我国梨生产现状及主要对策.中国果树,2003,(1),47～50.
12.郭善广.苹果浓缩汁褐变、后浑浊诱因及控制研究[硕士学位论文].陕西师范大学,2004.
13.郝慧英,赵光螯,徐岩.苹果中多酚氧化酶的性质.无锡轻工大学学报,2003,22(1),7～11.
14.何乃波.山东省水果资源及其产业发展问题与对策.中国人口资源与环境,2006,1(16),140～141.
15.胡小松,李积宏.现代果蔬汁加工工艺学.北京：中国轻工业出版社.1995,48～89.
16.纪花,陈锦屏.梨汁酶促褐变控制方法研究.食品工业.2007(2),17～18.
17.姜峥,苏政波.雪梨发酵酒的加工工艺研究.山东食品发酵,2007,(2),16～17.
18.鞠志国,朱广廉.水果贮藏期间的组织褐变问题.植物生理学通讯,1988,(4),46～48.
19.阚建全主编..食品化学.北京：中国农业大学出版社.2002,55～57.
20.李林.蔗汁美拉德反应及其抑制研究[硕士学位论文].广西大学,2001.
21.刘金豹,翟衡,张静.果汁褐变及其影响因素研究进展切.饮料工艺,2004,7(3)：1～4.
22.刘邻渭,季瑞溶,马成林.食品化学.陕西：陕西科学技术出版社.1996,43～48.
23.李鹏,彭辉,张天篇.不同抑制条件对梨汁褐变影响的研究.河北农业大学学报,1994,17(1),53～56.
24.李秀根,张绍铃.世界梨产业现状与发展趋势分析.中国果业信息,2006,11,1～5.
25.李秀根,杨健.我国梨果业生产现状、存在问题及发展对策.果农之友,2003,11,5～7.
26.马金峰.陈皮酸梨汁加工技术.食品研究与开发,1997,18(3),29～30.
27.马霞,王瑞明,关凤梅.果汁非酶褐变的反应机制及其影响因素.粮油加工与食品机械,2002.(9),46～48.
28.马霞,陈建文,关凤梅.苹果汁贮存过程中非酶褐变因素及其控制.山东轻工业学院学报,2001,15(4),52～55.
29.马霞,林炳芳.苹果汁加工过程中非酶褐变因素及其控制.山东轻工业学院学报,1998,12(4),32～37.
30.马霞,关凤梅,王瑞明.加工过程中添加剂对苹果汁非酶褐变的影响.食品科学,2002,(1),91～93.
31.乔勇进,张绍铃,陶书田,张振铭,刘招龙.梨果实石细胞发育机理的研究进展.果树学报,2005,22(4),367～371.
32.曲静然,马霞.贮藏过程中添加剂对浓缩苹果汁非酶褐变的影响.山东轻工业学院学报,2004,6,60～63.
33.宋宏新,高栋,赵伟伟.草每果肉果汁加工中变色因素分析.饮料技术,2002,5,45～47
34.任述荣,赵晋府.果汁风味劣变因素的研究.食品与发酵工业,2002,28(5),70～73.
35.闪崇辉.北京名果.北京：科学技术文献出版社.2004,90～91.
36.石碧,狄莹.植物多酚.北京：科学出版社.2000,19～20.
37.童军茂,左海清,杨艳彬,赵玉江.香梨浊汁饮料加工技术的研究.粮油加工与食品机械,2002,(3),49～51.
38.王坤范,陈秀芳.桃果实多酚氧化酶性质的研究．北京农业大学学报,1995,21(4),370～376.
39.王清章,彭光华,金悠.莲藕中酚类物质的提取分析及酶促褐变底物的研究.分析科学报,2004,20(1),38～40.
40.王素雅,王璋.香蕉汁加工过程中褐变原因初探.食品工业科技,2002,23(5),13～16.
41.吴燕华,李楠,刘文力.超滤膜在果汁加工中的应用研究闭.广东化工,2006,33(155),57～59.
42.吴震,别小妹,王和福.南果梨果实后熟过程生理生化变化的研究.沈阳农业大学学报,1997,28(2),111～115.
43.夏玉静,王文辉,贾晓辉,姜云斌,张志云,王志华,等.梨优良品种制汁性能研究.食品科学,2009,23,204～208.
44.许国能.杨梅品种果汁加工特性研究[硕士学位论文].浙江大学,2007.
45.徐芹.砀山酥梨果汁褐变机理及控制技术研究[硕士学位论文].南京农业大学,2008.
46.杨清香,于艳琴.果蔬加工技术.北京：化学工业出版社.2006,2～6.
47.杨毅.浓缩砀山酥梨汁非酶促褐变机理及其控制技术研究[博士学位论文].合肥工业大学,2007.
48.张素.不同梨品种加工特性及加工品质控制技术研究[硕士学位论文].山东农业大学,2008.
49.张晓辉,王济美,唐风侠.砀山酥梨果汁饮料的研制.软饮料工业,1997,48,21～23.
50.张添,钱合,刘长虹.影响芦荟制品非酶褐变的因素及其控制方法.无锡轻工业大学学报,2002,21(5),496～499.
51.张利奋.国际饮料分析方法.北京：中国轻工业出版社.1992,1～5.
52.赵彩平,张绍铃,徐国华.世界与中国的梨生产、贸易及流通现状.柑桔与亚热带果树信息,2005,21(2),5～7.
53.赵光远,李娜,纵伟.防褐变剂在混浊梨汁加工过程中的应用.保鲜与加工,2006,4(35),25～27
54.赵光远,李娜,纵伟.超高压处理对梨汁中多酚氧化酶活性的影响阴.食品与药品,2007a,9(1),15-18.
55.赵光远,张世涛,白艳红.高压处理对鲜榨苹果汁中微生物和酚类影响的研究闭.食品科技,2007b,5,69～72.
56.赵光远,王璋,许时婴.浑浊苹果汁加工中苹果PPO热失活条件的研究.食品科技,2003,7,84～87.
57.赵国华,陈宗道.含硫氨基酸食品功能性。粮食与油脂,1994,4,35～37.
58.赵坚华,郑玉淑,李官浩,权伍荣..苹果梨中多酚氧化酶抑制剂的抑制效果研究.食品科学,2010,31(2),277～279.
59.郑琳,纵松.蜂蜜梨汁果奶的研制..养蜂科技,2003,(2),31～34.
60. Adrian J. Nutritional and physiological consequences of the Maillard reaction.World Rev Nutr Diet, 1974,9,71～122.
61. Ajandouz E H, Puigserver A. Nonenzymatic browning reaction of essential amino acids:Effect of pH on caramelization and Maillard reaction kinetics. Agric Food Chem.,1999,47,1786～1793.
62. Avila I.M.,Silva C.L. Modeling kinetics of thermal degradation of color in peach puree. Journal of Food Engineering,1999,39(2),161～166.
63. Awad M A, Jager A. Flavonoid and chlorogenic acid concentrations in shin of 'Jonagold' and 'Elstar' apples during and after regular and ultra low oxygen storage. Postharvest Biology and Technology.2000,20,15～24.
64. Babsky N.E., Toribio, J.L., Lozano, J.E. Influence of storage on the composition of clarified apple juice concentrate. Journal of Food Science,1986,51(3),564～567.
65. Buedo A.P.,Elustondo, M.P.,Urbicain, M.J. Amino acid loss in peach juice concentrate during Storage. Innovative Food Seience & Emerging Technologies,2001,1,281～288.
66. Conn E.E. Chemical conjugation and compartment plant adaptation to toxic natural products.New York:Cellular and Molecular Biology of Plant Stress,1985,351～362.
67. Cornwell C.J.,Wrolstad R.E. Cause of browning in Pear juice concentrate during storage. Journal of Food Science,.1981,46(2):515～518.
68. Coseteng M.Y., Lee C.Y. Changes in apple polyphenol oxidase and polyphenol concentrations in relation to degree of browning. Journal of Food Science,1987,4(52),985～989.
69. Dolores M., Nieves C.M. Carmen Changes in the Amino Acid Composition of Dehydrated Orange Juice during Accelerated Nonenzymatic Browning. Agric. Food chem.,1998,46(1):277～280.
70. Garza S, Ibarz A., Pagan J., Giner J. Non-enzymatic browning in Peach Puree during heating. Food Research International,1999,32(5),335～343.
71. George A S, Ronald E W. Influence of variety, maturity, processing and storage on the phenolic composition of pear juice. Agric Food Chem.,1990,38(3),817～824.
72. Ghorai K., Khurdiya, D.S. Storage of heat processed Kinnow mandarin juice. Journal of Food Science and Technology,1998,35,422～424.
73. Hande S.B., Feryal K. Effect of storage on nonenzymatic browning of apple juice concentrates. Food Chemistry,2003,80,91～97.
74. Hendrickx M., Ludikhuyze L., Broeek I. Effects of high Pressure on enzymes related to food quality. Trends in Food Science and Technology,1998,9,197～203.
75. Hideki M, Takeru T, Reiko H, Tadaaki F. Cell wall changes in pear fruit softening on and off the tree. Postharvest Biology and Technology,1998,143～149.
76. Ibarz A., Pagan J., Garza S. Kinetic models for colour changes in Pear Puree during heating at relatively high temperatures. Journal of Food Engineering,1999,39,415～422.
77. Iyidogan N.F., Baymdirli, A. Effect of L-cysteine,kojic acid and 4-hexylresorcinol combination on inhibition of enzymatic browning in Amasya apple juice. Journal of Food Engineering,2004,62, 299～304.
78. Juinn C.H, David A.H, Brian M.Y. Effects of variety, maturity and processing on pear juice quality and protein stability. Journal of Food Science,1990,55(6),1610～1613.
79. Kacem B, Cornwell J. A, Marshall M. R. Nonenzymatic browning in aseptically packaged orange drinks effect of ascorbic acid, amino acids and oxygen. Food Sci.,1987,6,1668～1672.
80. Koca N., Selen B.H., Karadeniz F. Kinetics of nonenzymatic browning reaction in citrus juice concentrates during storage. Turkish Journal of Agriculture and Forestry,2003,27,353～360.
81. Kondo S, Tsuda K, Muto N. Antioxidative activity of apple skin or flesh extracts associated with fruit development on selected apple cultivars. Scientia Horticulture.2002,96,177～185.
82. Labuza, T.P., Lillemo, J.H., Taoukis, P.S. Inhibition of polyphenol oxidase by proteolytic enzymes. Fruit Processing,1992,2,9～13.
83. Lambrecht, H. S. Enzymatic browning and its prevention:Sulfite substitutes for the prevention of enzymatic browning in foods. ACS Symposium Series 600. Washington DC:American Chemical Society.1995,313～323.
84. Lozano J. E., Drudis-Biscari R., Ibarz A. Enzymatic browning in apple pulps. Journal of Food Science,1994,59(3),564～567.
85. Lozano J.E., Ibarz A. Color changes in concentrated fruit pulp during heating at high temperatures. Journal of Food Engineering,1997,31(3),365～373.
86. Marques L., Fleuriet, A., Macheix, J. Fruit polyphenol oxidase:new date on an old problem. Enzymatic browning and its prevention. Washington DC:American Chemical Society.1995, 90～102.
87. Martinez M.V., Whitaker, J.R. The biochemistry and control of enzymatic browning. Trends in Food Science and Technology,1995,6,195～200.
88. Masatsune M., Tsurutani M., Tomita M. Relationship between apple ripening and browning: Changes in polyphenol content and polyphenol oxidase. Agricultural and Food Chemistry, 1995,5(43),1115～1121.
89. Masatsune M, Yuki S., Seiichi H. International Congress Series.2002,1245:459～460.
90. Mayer A M, Harel E. Polyphenol oxidase in plants. Phytochemistry,1979,18,193～215.
91. Molnar-Perl I., Friedman M. Inhibition of browning by sulfur amino acids. Part 2. Fruit juices and beverages. CRC Critical Reviews in Food Science and Nutrition,1990a,32(3),253～273.
92. Molnar-Perl I., Friedman M. Inhibition of browning by sulfur amino acids. Part 3. Apples and potatoes. Journal of Agricultural and Food Chemistry,1990b,38,1652～1656.
93. Monsalve-Gonzalez A., Barbosa-Canovas G. V., Cavalieri R. P.,McEvily A. J., Iyengar R. Control of browning during storage of apple slices preserved by combined methods.4-Hexylresorcinol as antibrowning agent. Journal of Food Science,1993,58(4),797～800.
94. Moon K. D., Son S., Lee C. Y.. Inhibitory effects of various antibrowning agents on apple slices. IFT Annual Meeting 1999. Book of abstracts,1999,227.
95. Negishi O.,Ozawz T. Inhibition of enzymatic browning and protection of sulfhydrl enzymes by thiol compounds. Phytochemistry,2000, (54),481～487.
96. Ozoglu H, Baymdirh A. Inhibition of enzymic browning in cloudy apple juice with selected antibrowning agents. Food Control,2002,13,213～221.
97. Richard-Forget F. C., Goupy P. M., Nicolas J. J. Cysteine as an inhibitor of enzymatic browning, Part 2, kinetic studies. Journal of Agricultural Food Chemistry,1992,40(1),2108～2113.
98. Roiga M.G., Bellob J.E,Riverac Z.S. Kennedyc J.F. Studies on the occurrence of nonenzymatic browning during storage of citrus juice. Food Research International.1999,32,609～619.
99. Sandhu K.S. Singh N. Studies on the factors affecting the physico-chemical and organoleptic properties of kinnow juice. Journal of Food Science and Technology,2001,38,266～269.
100. Sanoner P, Guyat S, Marnet N. Polyphenol profiles of French ceder apple varieties. Journal of Agriculture and Food Chemistry,1999,47,4847～4853.
101. Shinoda,Y. Browning of model orange juice solution:Factors affecting the formation of decomposition Products. Bioscience, Biotechnology and Biochemistry,2005,69,2129～2137.
102. Sapers G. M., Hicks K. B., Phillips J. G., Garzarella L., Pondish D. L., Matulaitis R. M., et al. Control of enzymatic browning in apple with ascorbic acid derivatives, polyphenol oxidase inhibitors, and complexing agents. Journal of Food Science,1989,54(4),997～1002.
103. Shinoda Y. Browning of model orange juice solution:Factors affecting the formation of decomposition products. Bioscience, Biotechnology and Biochemistry,2005,69,2129～2137.
104. Vamos-Vigyazo L. Enzymatic browning and its prevention in fruits and vegetables ACS Symposium Series (600). Washington DC:American Chemical Society.1995,49～62.
105. Wakayama, T. Polyphenol oxidase activity in Japanese apples differences among cultivates and prevention by heat, ascorbic acid, and reduced oxygen. Enzymatic browning and its prevention. Washington DC:American Chemical Society.1995,251～266.
106. Walker, J. R. L. Enzymatic browning and its prevention. ACS Symposium Series (600). Washington DC:American Chemical Society.1995,8～22.
107. Yucheng Fu, Kaili Zhang, Niya Wang, Jinhua Du. Effects of aqueous chlorine dioxide treatment on polyphenol oxidases from Golden Delicious apple. Science and Technology,2007,10,1～7.
108. Zandrie B.,Vuralq G., Herry H.N. Selective removal of Polyphenols and brown colour in apple juices using PES/PVP membranes in a single ultrafiltration Process. Separation and Purification Technology,2001,53～61.
109. Zemel G. P, Sims C. A, Marshall M. R. Low pH inactivation of polyphenol oxidase in apple juice. Journal of Food Science,1990,55 (2),562～565.
