Formation of methyl ketones as artifacts during steam distillation of Cheddar cheese and butter-oil

Author:

Lawrence R. C.

Abstract

SummaryA complete range of methyl ketones with odd numbers of carbon atoms from C3 to C15 was isolated by steam distillation at atmospheric pressure from fresh butter-oil, cream and Cheddar cheeses of various ages. Evidence was produced to show that the greater part of these methyl ketones was formed during the heat treatment of milk fat. The maximum quantities of methyl ketones obtainable from butter-oil, determined by exhaustive steam distillation at atmospheric pressure, averaged from 14 ppm. for undecan-2-one to 46 ppm. for pentadecan-2-one. Some artifact formation of methyl ketones also occurred, although to much less extent, when dairy products containing milk fat were steam distilled under reduced pressure at 40 °C. Possible mechanisms of formation of the methyl ketones are discussed.Since it proved possible to extract methyl ketones in low concentration from mature cheese at room temperature, it is evident that milk fat may contain precursors which break down to methyl ketones slowly during cheese ripening, this breakdown being accelerated at higher temperatures. Methyl ketones may therefore play a part in Cheddar flavour, but a previous report from this Institute that the time of first appearance of certain methyl ketones of odd numbers of carbon atoms above C5 in steam distillates, at atmospheric pressure from Cheddar cheese, coincided with the appearance of the typical Cheddar flavour was not confirmed.

Publisher

Cambridge University Press (CUP)

Subject

Animal Science and Zoology,General Medicine,Food Science

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3