The effect of ethylene on chlorophyll degradation in the peel of Robinson tangerine (X Citrus reticulata Blanco) and calamondin (X Citrofortuneila mitis IBlancol Ingram and Moore) fruits was studied. The chlorophyD degrading system in the peel of these two citrus species was not selfsustaining but required ethylene to function. Chlorophyl degradation ceased immediately when fruit were removed from ethylene and held in ethylene-free air at 0.2 atmospheric pressure. However, at atmospheric pressure, chlorophyDl degradation continued for 24 hours in the absence of exogenous ethylene. Although chlorophyliase levels were negatively correlated with chlorophyll content in the peel (r = -0.981; P < 0.01), the level of chlorophyDase activity did not change when fruit were removed from ethylene, even though chlorophyDl degradation had stopped. From these observations, it was concluded that ethylene is necessary for chlorophyH degradation in the two species of citrus studied, but its primary role is not solely for the induction of chlorophyllase activity.

BHA, BHT, rosemary extract, and a-tocopherol were incorporated into low-density polyethylene (LDPE) at the 0.1% level and thermoformed into 25-mm-dia, 0.25-mm-thick discs, which were exposed to the surface of fresh beef and held in contact with a polyvinyl chloride (PVC) overwrap. On d 0, the control treatment with only the PVC overwrap had greater "a" (redness) values, probably due to greater transmission of oxygen to the meat surface. However, by d 7, the control with only the PVC overwrap had lower redness values than any of the other treatments. By d 8 and 9, the meat packaged with the BHA-impregnated film had higher "a" (redness) values than any of the other film treatments

Chopped `Salinas' crisphead lettuce (Lactuca sativa L.) was packaged in four types of polymeric films and stored at 1 or 5C for 14 days. Discoloration and off-flavors developed in lettuce stored in the two films in which the naturally produced CO2 rose above 20%. In the two films (oriented low-density polyethylene) with O2 transmission rates higher than 3000 ml·m-2· day-1·atm-1 at 22C, CO2 remained below 20%, O2 was between ≈ 2% and 15%, and the lettuce was acceptable after 14 days of storage at either 1 or 5C. Appearance and flavor were affected more by temperature than by length of storage.

No abstract

A method for fish species identification by isoelectric focusing of sarcoplasmic proteins on LKB Ampholine PAGplates, pH 3.5–9.5, was collaboratively studied to determine whether photographs of protein patterns from authentic species could be used to identify unknown samples. Seven collaborators were sent 8 unknown samples in duplicate to identify from an 8 × 10 in. photograph of an Ampholine PAGplate showing standard protein patterns from 14 species of fish. The 7 collaborators identified the unknown samples with 93% accuracy. Eight of 14 monkfish samples were not identified correctly and showed protein patterns different from the protein patterns shown in the photographic standard. All of the incorrectly identified samples showed the same protein pattern. The other 7 unknown species were all correctly identified. The method has been adopted as official first action.