Rogel-Castillo Cristian, Zuskov David, Chan Bronte Lee, Lee Jihyun, Huang Guangwei, Mitchell Alyson E
Department of Food Science and Technology, University of California Davis , One Shields Avenue, Davis, California 95616, United States.
Almond Board of California, 1150 Ninth Street, Suite 1500, Modesto, California 95354, United States.
J Agric Food Chem. 2015 Sep 23;63(37):8234-40. doi: 10.1021/acs.jafc.5b03121. Epub 2015 Sep 8.
Concealed damage (CD) is a brown discoloration of nutmeat that appears only after kernels are treated with moderate heat (e.g., roasting). Identifying factors that promote CD in almonds is of significant interest to the nut industry. Herein, the effect of temperature (35 and 45 °C) and moisture (<5, 8, and 11%) on the composition of volatiles in raw almonds (Prunus dulcis var. Nonpareil) was studied using HS-SPME-GC/MS. A CIE LCh colorimetric method was developed to identify raw almonds with CD. A significant increase in CD was demonstrated in almonds exposed to moisture (8% kernel moisture content) at 45 °C as compared to 35 °C. Elevated levels of volatiles related to lipid peroxidation and amino acid degradation were observed in almonds with CD. These results suggest that postharvest moisture exposure resulting in an internal kernel moisture ≥ 8% is a key factor in the development of CD in raw almonds and that CD is accelerated by temperature.
隐蔽损伤（CD）是坚果仁的一种褐色变色现象，仅在果仁经过适度加热（如烘烤）后才会出现。确定促进杏仁中隐蔽损伤的因素对坚果行业具有重大意义。在此，采用顶空固相微萃取-气相色谱/质谱联用技术研究了温度（35和45℃）和水分含量（<5%、8%和11%）对生杏仁（Prunus dulcis var. Nonpareil）中挥发性成分组成的影响。开发了一种CIE LCh比色法来鉴定有隐蔽损伤的生杏仁。与35℃相比，45℃下暴露于水分（果仁水分含量8%）的杏仁中隐蔽损伤显著增加。在有隐蔽损伤的杏仁中观察到与脂质过氧化和氨基酸降解相关的挥发性成分水平升高。这些结果表明，收获后水分暴露导致果仁内部水分≥8%是生杏仁中隐蔽损伤发生的关键因素，并且隐蔽损伤会因温度升高而加速。
