title: Effect of Temperature and Moisture on the Development of Concealed Damage in Raw Almonds (Prunus dulcis).
abstract: 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.
authors: Department of Food Science and Technology, University of California Davis , One Shields Avenue, Davis, California 95616, United States.
authors: Cristian
authors: C
authors: Rogel-Castillo
authors: Department of Food Science and Technology, University of California Davis , One Shields Avenue, Davis, California 95616, United States.
authors: David
authors: D
authors: Zuskov
authors: Department of Food Science and Technology, University of California Davis , One Shields Avenue, Davis, California 95616, United States.
authors: Bronte Lee
authors: BL
authors: Chan
authors: Department of Food Science and Technology, University of California Davis , One Shields Avenue, Davis, California 95616, United States.
authors: Jihyun
authors: J
authors: Lee
authors: Almond Board of California, 1150 Ninth Street, Suite 1500, Modesto, California 95354, United States.
authors: Guangwei
authors: G
authors: Huang
authors: Department of Food Science and Technology, University of California Davis , One Shields Avenue, Davis, California 95616, United States.
authors: Alyson E
authors: AE
authors: Mitchell
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D003124:Colorimetry / Q000379:methods; D005519:Food Preservation / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D006358:Hot Temperature; D006813:Humidity; D015227:Lipid Peroxidation; D009754:Nuts / Q000737:chemistry* / Q000378:metabolism; D000068181:Prunus dulcis; D013696:Temperature; D055549:Volatile Organic Compounds / Q000032:analysis; D014867:Water / Q000032:analysis*
chemical_list: D000596:Amino Acids; D055549:Volatile Organic Compounds; D014867:Water
keywords: HS-SPME-GC/MS; Nonpareil; Prunus dulcis; almond; color; concealed damage; gas chromatography; mass spectrometry; volatiles