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Carrot shreds, sticks and slices were dipped in solutions of CaClz alone, or with chlorine and stored at 0, 5 or 10°C to determine the effects of calcium (Ca) on storage quality. A 0.5% or 1% CaCl, treatment maintained firmness and reduced microbial growth of carrot shreds at all temperatures. These treatments also resulted in lower tissue pH than in the water-dipped controls. Treatments increased Ca content slightly in sticks and slices and substantially in shreds and had no effect on storage quality of sticks or slices.

Fresh-cut cantaloupe cubes were placed in film-sealed containers in which the internal gas mixture was attained naturally (nMAP), was flushed with 4 kPa O 2 plus 10 kPa CO 2 (fMAP), or was maintained near atmospheric levels by perforating the film (PFP). While both nMAP and fMAP maintained the salable quality of melon cubes for 9 d at 5 ЊC, fMAP maintained quality better than nMAP. The benefit of fMAP was indicated by better color retention, and by reduced translucency, respiration rate, and microbial population compared with nMAP. Shelf life of cubes in PFP was only 5 to 7 d at 5 ЊC, and its rapid decline was due to tissue translucency and/or off-odor development.

Ethylene had an undesirable effect on the quality of kiwifruits, bananas, broccoli, and spinach leaves that were prepared and stored as lightly processed products. A 2.or 20 ppm ethylene treatment hastened the softening of the pulp of kiwifruits and bananas held at 20°C. Use of charcoal with palladium chloride, as ethylene absorbent, prevented the accumulation of the ethylene and was effective in reducing the rate of softening in kiwifruits and bananas and of chlorophyll loss in spinach leaves, but not in broccoli.

Degradation of chlorophyll in spinach (Spinacia olearacea L. cv. Hybrid 612) appeared to be regulated through the peroxidase-hydrogen peroxide pathway, which opens the porphyrin ring, thus resulting in a colorless compound. This conclusion was arrived at from the analysis of chlorophylls (Chls) and their metabolizes by HPLC and of enzyme activities catalyzing the degradative reactions. Chls decreased at 25C but not at 1C. The chlorophyll oxidase pathway was not active, as noted by the lack of accumulation of a reaction product named Chl a-1. Lipid peroxidation increased with storage, but the products of the reaction. did not degrade chlorophyll, as noted by the lack of increase in Chl a-1. Chlorophyllase activity increased, but chlorophyllide, the expected product of the reaction, changed minimally during senescence. Ethylene at 10 ppm did not alter the pathway that degraded chlorophyll in spinach.

Three β‐galactosidase (EC 3. 2. 1. 23) isozymes were purified from the mesocarp of ripe fruit of Persea americana Mill. cv. Lula. and their effects on pectin derived from mature‐green tomato fruit were investigated. The β‐galactosidases had pl values of 5. 0,5. 1 and 5. 2. and molecular weights of 41. 49 and 54 KDa. respectively. There was a partial degradation of pectin resulting in the release of monomeric galactose upon treatment with avocado β‐galactosidase. This degradation resulted in increased pectin solubility and decreased apparent average molecular size as determined by microfiltration and gel permeation by high‐performance liquid chromatography. The increase in solubility was due. in part. to an apparent decrease in the ability of pectin molecules to aggregate together.

YBSTRACT Chemical and sensory attributes of table-ripe tomatoes harvested at different stages of maturity were evaluated. Intensities of nine sensory attributes were similar in table-ripe tomatoes harvested at the "mature-green" and "breaker" stages. Intensities of "sweetness," "saltiness" and "fruity-floral" flavor were higher in tomatoes harvested at the "table-ripe" stage than at earlier stages of maturity. Desirability of tomatoes was closely associated with the fruity-floral attribute. Variations of sensory attributes were due to volatile and nonvolatile components. The amount of the variation explained by the components generally increased when the areas of the volatile peaks were converted to logarithms for the stepwise regression analysis.