主题：【已应助】求助英文文献4篇，请帮帮忙，谢谢啦！

【篇  号】：1
【题  名】：Ester Content and Jelly pH Influences on the Grade of Pectins
【作  者】：CHRISTIAN J. B. SMIT, EDWIN F. BRYANT
【期刊名全称】：Journal of Food Science
【文献页码】： Volume 33, Issue 3, pages 262–264, May 1968 
【全文链接】:http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2621.1968.tb01363.x/abstract

【篇  号】：2
【题  名】：EFFECT OF DRYING ON PECTIN MADE FROM LIME AND LEMON POMACE 
【作  者】：P. G. CRANDALL, R. J. BRADDOCK, A. H. ROUSE
【期刊名全称】：Journal of Food Science
【文献页码】： Volume 43, Issue 6, pages 1680–1682, November 1978 
【全文链接】:http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2621.1978.tb07387.x/abstract

【篇  号】：3
【题  名】：DEMETHYLATION OF PECTIN USING ACID AND AMMONIA 
【作  者】：W. J. KIM,†, C. J. B. SMIT, V. N. M. RAO
【期刊名全称】：Journal of Food Science
【文献页码】： Volume 43, Issue 1, pages 74–78, January 1978 
【全文链接】:http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2621.1978.tb09739.x/abstract

【篇  号】：4
【题  名】：SETTING TIME AND SETTING TEMPERATURE OF PECTIN JELLIES
【作  者】：J. J. DOESBURG, G. GREVERS
【期刊名全称】：Journal of Food Science
【文献页码】：Volume 25, Issue 5, pages 634–645, September 1960
【全文链接】:http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2621.1960.tb00008.x/abstract