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  • Author or Editor: Alfredo R. Gonzalez x
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Abstract

Firmness values were determined for isogenic normal and rin tomato fruits (Lycopersicon esculetum Mill.) that were held at 20°C in air or 10 ppm ethylene. Exogenous ethylene induced a slight increase in softening of detached rin fruits but these fruits do not soften as much as normal fruit. A two step sequence for softening is postulated.

Open Access

Abstract

Changes in reduced ascorbic acid in normal tomato fruits (Lycopersicon esculentum Mill.) during holding at 20°C seem to be related to ripening. No change in reduced ascorbic acid levels from mature green to yellow rin fruits was observed when detached from the plant. Apparently, a reduction mechanism from dehydro to reduced ascorbic acid is active in normal tomatoes but inactive in detached rin fruits. This mechanism was operative in normal and rin fruits left on the plant. Exogenous ethylene (10 ppm) neither affected reduced ascorbic acid levels in normal and rin fruits, nor the total ascorbic acid in normal fruits. Maintenance of initial levels of total ascorbic acid was noted in ethylene treated rin fruits. Similar total ascorbic acid levels were found in normal and rin fruits held on the vine to the red and yellow stages, respectively; and were higher than in comparable fruits held in storage.

Open Access

Abstract

A single application of 20 ppm gibberellic acid (GA3) 2 weeks before harvest increased yields and height of fall spinach (Spinacia oleracea L.) by inducing the setting of leaves in an upright position and stimulating petiole and stem growth. Small differences were noted between GA3-treated and untreated overwintered spinach. Cultivars responded similarly to growth conditions and to GA3 application. Both GA3-treated and untreated fall spinach had better quality than overwintered spinach harvested in the spring. Spinach treated with GA3 had higher shearpress values, yellow and green color, lower titratable acidity, and no change in pH values as compared to the control. A panel graded GA3-treated spinach slightly higher in amount of petioles and stems and lower in general acceptability than the untreated control. Better utilization of GA3 was obtained in the fall-grown spinach.

Open Access

Abstract

A comparison was made of ‘Ozarka’ and ‘Green Valley’ spinach (Spinacia oleracea L.) planted in early fall, and harvested in the fall and spring; and planted in late fall and harvested once in the spring. Fall-harvested spinach had no stems, low percentage petioles, and high percentage leaf blades with better green color and lower shear values, pH and titratable acidity as well as higher sensory evaluations than spring-harvested. Spring-harvested spinach from the late fall planting had a higher percentage of undersirable stems and petioles than spring-harvested spinach from the early fall planting.

Open Access

A study was conducted to test alternative production practices that lessen the use of carbamate fungicides in the field and post-harvest washing techniques that help to reduce carbamate residues in canned spinach. Five spinach genotypes showed a high degree of resistance to white rust, the predominant field disease. The fungicide Ridomil used alone or combined with copper or Maneb provided the best control in susceptible cultivars. Maneb alone or combined with copper controlled white rust but not as efficiently as Ridomil. The most efficient washing methods to remove Maneb residues were washing with a detergent solution plus water or ozonated water or a triple wash with detergent, water and ozonated water. The lowest residue levels of ethylenethiourea (ETU), a carcinogenic carbamate derivative, detected in the washing treatments was in the range of 0.15 to 0.45 ppm. ETU in the non-washed controls fluctuated from 0.85 to 2.31 ppm.

Free access

Abstract

The processing quality of kidney, pinto, and small white beans (Phaseolus vulgaris cv Redkloud, UI-111, and Aurora) was compared when harvested at the dry (11–14% moisture content) and semi-dry (50–60% moisture content) stage in the spring and fall growing seasons. Semi-dry harvested beans were canned immediately after harvest and after being storaged at 27°C for 24 hours. Dry harvested beans were canned after harvest. The respiratory rate of semi-dry harvested beans stored at 27° decreased with time in storage. Significant differences in objective and subjective evaluations were found between cultivars, harvest stage, storage treatments, and spring and fall growing seasons. Semi-dry harvested beans stored for 24 hours at 27° had fewer split beans than the non-stored counterpart and the dry harvested beans. Semi-dry beans with and without storage treatment were firmer than those harvested dry. An increase in color was observed in semi-dry beans of ‘UI-111’ and ‘Redkloud’ after being stored for 24 hours at 27°. Sensory panel evaluations indicated that beans harvested at the semi-dry stage and stored for 24 hours at 27° before canning had similar or higher acceptability than beans harvested dry.

Open Access

Abstract

The 3 harvesters tested provided about the same harvest efficiency. Harvesters did not show significant differences in sound, broken, and bruised pods harvested from 2 fields. More pod clusters and less trash were obtained in the field with more mature pods. Under the same field conditions, 2.6 times more snap beans could be harvested with the FMC model GB-110 and Chisholm-Ryder Multi-Density than with the Chisholm-Ryder Hi-Boy. Quality differences of canned beans harvested with the machines were too small to differentiate by the USDA standards for grades of canned snap beans.

Open Access