The natural environment is composed of various potentially hostile stressors. It is a basic requirement of life that the cells of an organism must be maintained within closely defined physiological limits. The maintenance of a constant interior mileu results from physiological and behavioural homeostatic adaptations. The physiological regulation of homeostatis is achieved by complex endocrine interactions, principally by the hormones secreted from the adrenal glands. In this brief review the responses of the avian adrenal glands to stressful stimuli, the mechanism of adrenal activation, and the function of the adrenal responses will be considered.

A factorial plus supplemental central composite experimental design was used to assess quantitatively the effects and interactions of temperature (5°–37°C), pH (4.5–7.5), NaCl (5–45 g/1), NaNO2 (0–1000 μg/ml), and atmosphere (aerobic vs. anaerobic) on the growth kinetics of Listeria monocytogenes Scott A in Tryptose Phosphate Broth. A total of 709 growth curves were generated, with individual curves fitted using non-linear regression analysis in conjunction with the Gompertz function. The results were analyzed by response surface analysis to generate a cubic model to predict the growth of L. monocytogenes in response to any combination of the variables within the specified ranges. Evaluation of the model indicated that it can be used to provide reasonable “first estimates” of the impact of food formulation and storage conditions on the growth of L. monocytogenes, and can be automated readily to develop “user-friendly” software.

Novel browning inhibitors were evaluated in raw apple juice and on the cut surface of apple plugs, using quantitative measurements of color changes during storage to assess treatment effectiveness. Ascorbic acid-2-phosphate (AAP) and -triphosphate (AATP) showed promise for cut surfaces but were ineffective in juice. Ascorbic acid-6-fatty acid esters showed anti-browning activity in juice. Cinnamate and benzoate inhibited browning in juice but induced browning when applied to cut surfaces. Combinations of P-cyclodextrin with ascorbic acid (AA), AAP or ascorbyl palmitate were effective in juice but not on cut surfaces. Combinations of AA with an acidic polyphosphate were highly effective with both juice and cut surfaces.

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Crispness and crunchiness are important factors in the enjoyment of many foods, but they are defined differently among dictionaries, consumers, and researchers. Sensory, mechanical, and acoustic methods have been used to provide data on crispness and crunchiness. Sensory measurements include biting force and sound intensity. Mechanical techniques resemble mastication and include flex, shear, and compression. Acoustical techniques measure frequency, intensity, and number of sound events. Water and oil content contribute to crispness and crunchiness, which also have temporal aspects. Information in the literature is compared in this article to develop definitions of crispness and crunchiness.A dense-textured food which, when chewed with the molars, undergoes a series of fractures while emitting relatively loud, low-pitched sounds. CONCLUSIONSFurther work on differentiating and defining crispy and crunchy textures is needed so that universal standards can be obtained. Such definitions could be translated into any 960 TUNICK ET AL. language and would be applicable to fruits, vegetables, baked foods, extruded foods, etc. Research in our laboratory, described in a subsequent article, [74] represents a step in that direction.