No abstract

Alterations of cucumber‐, melon‐like notes in aromas and flavors caused by retro‐aldol degradations oft2,c6‐nonadienal were confirmed using gas chromatographic measurements of volatile compounds in model systems. The data indicated that 3‐hydroxy‐c6‐nonenal was formed first by the addition of water to the alpha/beta double bond oft2,c6‐nonadienal, and this was followed by a retro‐aldol condensation of 3‐hydroxy‐c6‐nonenal to yieldc4‐heptenal and ethanal. Compared to the reaction rate in aqueous systems at neutral pH, formation ofc4‐heptenal was enhanced substantially at alkaline pH, but was greatly diminished at acidic pH values. Heating (to 90 C) of aqueous model systems oft2,c6‐nonadienal held at neutral pH also enhanced the rate of formation ofc4‐heptenal substantially compared to that at ambient temperature (21 C). Rates of formation ofc4‐heptenal in aqueous model systems held under air or nitrogen atmospheres were similar.c4‐Heptenal was not formed whent2,c6‐nonadienal was held at 21 C for 96 hr under air or nitrogen in nonaqueous commercial corn oil.

Volatile headspace compounds collected on Tenax GC at room temperature (21 °C) from pure cultures of Penicillium caseicolum and Penicillium camemberti grown on potato dextrose and Czapek's agar were separated by gas chromatography and identified by mass spectrometry, retention indices (/E), and odor quality. P. camemberti and P. caseicolum produced similar volatile compound profiles. Mushroom-like, green plant-like aromas were contributed by l-octen-3-ol, l,5-octadien-3-ol, l,5-octadien-3-one, 3-octanol, and 3-octanone. 2-Methylisoborneol contributed strongly to the overall musty/moldy component of aromas of Penicillium cultures. 2-Methoxy-3-isopropylpyrazine was found in aged mold cultures (4-6 weeks) only and caused these cultures to exhibit intense earthy/raw potato aromas.

No abstract

Rosemary oleoresin (20 ppm) was used as an antioxidant in turkey breakfast sausages prepared with 75% hand deboned turkey meat and 25% mechanically deboned turkey meat. It was compared to similarly formulated products with butylated hydroxyanisole/butylated hydroxytoluene (BHAIBHT, 200 ppm) and a control with no antioxidants. 2-Thiobarbituric acid-reactive substances in samples stored at 4°C demonstrated that rosemary oleoresin was comparable to a commercial blend of BHA/BHT/citric acid in suppressing lipid autoxidation. Sensory analysis was in agreement with these results. Analysis of volatile aroma compounds revealed the occurrence of oxidatively derived carbonyls in the sausages without antioxidants, while the antioxidanttreated sausages were essentially free from these carbonyls.