EFFECT OF AMMONIA EXPOSURE ON SUBSEQUENT RANCID FLAVOR DEVELOPMENT IN LAMB

Lamb exposed to ammonia in the event of refrigeration leakage is judged to be contaminated if the meat pH has increased 1.0–1.5 units or more above normal values, but the effect of smaller ammonia concentrations is not known. The left loins from 80 lamb carcasses, processed to Accelerated Conditioning and Aging (AC&A) specifications, were exposed to ammonia gas to give an increase in pH of 0.5 unit (40 loins) or 1.0 unit (40 loins). The right loins served as paired controls. Loins were frozen and held at –20C until they were assessed for rancid flavors by a trained taste panel. Loins were assessed after 3, 6, and 12 months storage. High-ammonia samples developed a level of rancid flavors likely to be detected by consumers after 3 months storage, and low-ammonia samples after 6 months. Therefore, pH cannot be used as a measure of ammonia contamination, as exposure causing only a 0.5 pH unit rise, which is within the normal pH range of lamb, severely reduced the frozen storage life.     

EFFECT OF SULFUR SUPPLY ON ALLIINASE, THE FLAVOR GENERATING ENZYME IN ONIONS

The characteristic flavor of onions occurs when the enzyme alliinase (EC 4.4 1.4) hydrolyzes S‐alk(en)yl‐L‐cystene sulfoxides (ACSOs) to form sulfur‐containing volatiles, pyruvate and ammonia. Two onion cultivars, Pukekohe Longkeeper and Grano, were grown to maturity at a high (4.0 meq S/L) and low (0.25 meq S/L) sulfur supply and assayed for alliinase specific activity and enzymatically produced pyruvate. Alliinase specific activity was greater (1.3–1.7 fold) at low sulfur supply in bulbs of both cultivars. Levels of enzymatically produced pyruvate were lower at low sulfur supply. Low sulfur supply has been previously shown to decrease levels of ACSOs and their biosynthetic intermediates but increase levels of proteins involved in sulfate uptake and mobilization. Alliinase may have an endogenous role in remobilizing ACSOs during conditions of sulfur deprivation.     

INTERVIEW INTERACTION OF REPRESSORS AND SENSITIZERS.

RESEARCH WITH QUANTITATIVE VARIABLES IN THE INTERVIEW HAS DEMONSTRATED THAT INTERVIEWEE VERBAL PATTERNS CAN BE MODIFIED BY MANIPULATION OF INTERVIEWER VERBAL PATTERNS. IT WAS PREDICTED THAT SENSITIZERS AND REPRESSORS, HAVING IDIOSYNCRATIC RESPONSE STYLES, WOULD AS INTERVIEWERS DIFFER IN THEIR BEHAVIOR AND THAT THESE DIFFERENCES WOULD RESULT IN DIFFERENT VERBAL BEHAVIOR BY THEIR RESPECTIVE INTERVIEWEES. REPRESSOR, SENSITIZER, AND NEUTRAL INTERVIEWERS WERE PAIRED WITH NEUTRAL INTERVIEWEES IN A 15-MIN INTERVIEW. SENSITIZER INTERVIEWERS TOOK MORE OF AN ACTIVE ROLE, AND THEIR INTERVIEWEES LESS THAN THAT OF REPRESSORS AND NEUTRALS. THE EFFECT OF INTERVIEWER PERSONALITY ON INTERVIEWER AND INTERVIEWEE SPEECH, AND THE ROLE OF INTERVIEW STRUCTURE ARE DISCUSSED. (16 REF.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)