| Title: | Effect of roasting conditions on color and volatile profile including HMF level in sweet almonds (Prunus dulcis) |
| Address: | "Department of Food Science and Technology, Ohio State University, Columbus, OH 43210, USA" |
| DOI: | 10.1111/j.1750-3841.2012.02629.x |
| ISSN/ISBN: | 1750-3841 (Electronic) 0022-1147 (Linking) |
| Abstract: | "Microwave, oven, and oil roasting of almonds were used to promote almond flavor and color formation. Raw pasteurized almonds were roasted in a microwave for 1 to 3 min, in an oven at 177 degrees C for 5, 10, 15, and 20 min; and at 135 and 163 degrees C for 20 min, and in oil at 135, 163, and 177 degrees C for 5 min and 177 degrees C for 10 min. Volatile compounds were quantified in the headspace of ground almonds, both raw and roasted, by selected ion flow tube mass spectrometry. Strong correlations were found between L value, chroma, and 5-(hydroxy methyl)-2- furfural; and were independent of roasting method. Raw almonds had lower concentrations of most volatiles than roasted almonds. Conditions that produced color equivalent to commercial samples were 2 min in the microwave, 5 min at 177 degrees C in the oven, and 5 min at 135 degrees C in oil. Microwave heating produced higher levels of most volatiles than oven and oil roasting at commercial color. Sensory evaluation indicated that microwave-roasted almonds had the strongest aroma and were the most preferred. Oil-roasted almonds showed significantly lower levels of volatiles than other methods, likely due to loss of these volatiles into the oil. Alcohols such as benzyl alcohols and strecker aldehydes including benzaldehyde and methional were at higher concentrations than other volatiles in roasted almonds. The oxidation of lipids to form alkanals such as nonanal and degradation of sugars to form furan type compounds was also observed. The Maillard reaction contributed to the formation of more of the total volatiles in almonds than the lipid oxidation reaction. PRACTICAL APPLICATION: The level of 5-(hydroxy methyl)-2- furfural (HMF), color, volatile profile, and sensory perception can be used to develop the best roasting method, time, and temperature for almonds. The rate of color development and the production of volatiles differ under different roasting conditions. Based on the color, volatile, and sensory assessments of the 3 almonds, the use of microwave technology as a process for roasting almonds reduces processing time and leads to an almond product with better flavor than oven or oil roasting" |
| Keywords: | Color Cooking/*methods Cottonseed Oil/chemistry Dietary Fats/analysis/radiation effects Food Preferences Furaldehyde/analogs & derivatives/analysis Hot Temperature Humans Maillard Reaction Mass Spectrometry Microwaves Nuts/*chemistry/radiation effects Odo; |
| Notes: | "MedlineAgila, Amal Barringer, Sheryl eng Comparative Study 2012/03/21 J Food Sci. 2012 Apr; 77(4):C461-8. doi: 10.1111/j.1750-3841.2012.02629.x. Epub 2012 Mar 19" |
