Seasonal Changes Occurring in the Pectinesterase Activity and Pectic Constituents of the Component Parts of Citrus Fruits.

Rouse, A. H.; Atkins, C. D.; Moore, E. L.

doi:10.1111/j.1365-2621.1962.tb00120.x

Cited by 37 publications

(28 citation statements)

References 3 publications

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“…All tissues contained TT-PME although its relative proportion in tissue extracts varied from 0.2% (peel DP) to 5.6% (juice DP). Data from Rouse et al (1962) suggest that tissues from these fruit contained near the seasonal average for PME activity. At room temperature and 4ЊC, peel HDS (100% TT-PME) destabilized the juice cloud more rapidly than other extracts.…”

Section: Discussionmentioning

confidence: 94%

Citrus Tissue Extracts Affect Juice Cloud Stability

Cameron

Baker

Grohmann

1997

Journal of Food Science

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Salt extractable proteins were isolated from hand expressed juice, rag and peel of Valencia oranges. Each tissue extract was divided into dialysis supernatant (DS) and precipitate (DP) (forms during dialysis). DP, DS and DS heated for 2 min at 80ЊC (HDS) were added to pasteurized, reconstituted frozen concentrated orange juice at 5 U ⅐ mL Ϫ1 of pectinmethylesterase. Samples were incubated either at 25ЊC for 14 days or 4ЊC for 28 days and periodically sampled to determine the effects of tissue extracts on juice cloud stability. Tissue specific differences were observed for the rate of juice cloud precipitation and among the HDS, DS, and DP fractions of a given tissue. HDS fractions destabilized juice cloud more rapidly than DS or DP at both 25 and 4ЊC.

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Section: Discussionmentioning

confidence: 94%

Citrus Tissue Extracts Affect Juice Cloud Stability

Cameron

Baker

Grohmann

1997

Journal of Food Science

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“…The total amount of pectic sustances was determined following enzymic digestion on a separate 100-mg sample of the AIS preparation and was found to equal within 10% the sum of the above fractions. The quantity of the pectic material in each fraction was determined by the colorimetric carbazole method (30). The residue from the total pectin extraction was extracted first for 2 h at 100°C in 5% NaOH to release a hemicellulose fraction, and then the residue was treated according to Updegraff to obtain the cellulose fraction (33).…”

mentioning

confidence: 99%

Mode of Action of Plastic Film in Extending Life of Lemon and Bell Pepper Fruits by Alleviation of Water Stress

Ben-Yehoshua¹,

Shapiro²,

Chen³

et al. 1983

Plant Physiol.

130

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The mechanism by which seal-packaging individual fruit in high density polyethylene film delays deterioration was ration of other perishable, living fruit items.The control of deterioration of fruit by plastic film had been generally explained by the modification of the concentrations of C02, 02, and ethylene (21). However, this theory was not supported by our data (1O, 13). Endogenous levels ofthe above gases were similar in fruit sealed in HDPE or not sealed, but their rates of physiological deterioration were altogether different. The major effect of sealing appears to be the provision of a watersaturated microatmosphere (8). This may alleviate water stress, which is important in controlling life processes (15, 20). However, so far only the inhibition of transpiration, shrinkage, and shriveling has been ascribed to the high humidity that is found in the microatmosphere of the sealed fruit (21). Therefore, we set out to investigate the hypothesis that sealing delays deterioration of lemon and bell pepper fruits by alleviating water stress. The importance of transpiration as a major process leading to physiological deterioration of citrus fruit has been demonstrated (7). This paper reports our attempts to relate water stress to various physiological parameters in sealed and nonsealed fruit. Lemons and peppers were selected for these studies because they responded very favorably to the seal-packaging technique. These fruits do not have the marked ripening and climacteric processes that could disturb our objective by masking the effects of the sealing per se on fruit behavior. Among the various techniques developed to extend fruit postharvest life, the use of plastic film is growing in importance because it is convenient in the many different conditions throughout the chain of handling from producer to consumer (8, 21). Ben-Yehoshua (8) found that seal-packaging individual fruit with a thin film ofHDPE2, 5 to 15 ,m in thickness, doubled storage life of various fruits. The flavor of the fruit was not spoiled; on the contrary, the sealed fruit maintained its normal flavor, as well as its firmness and fresh appearance for at least twice as long as nonsealed fruit. Surprisingly, sealed citrus fruit kept at 20C lost less weight and was firmer than nonsealed fruit at optimal (lower) temperatures.Seal-packaging delayed several parameters of physiological deterioration of fruit better than cooling; which is usually considered the best means of delaying senescence of detached living organs (1 1, 21). Accordingly, it is hoped that the elucidation of the mode of this action of seal-packaging would also help better understand the mechanism of senescence of detached plant organs and their causes. Such information might also be useful 2Abbreviations: HDPE, high density polyethylene; WSA, water-saturated atmosphere; WSD, water saturation deficit; AIS, alcohol-insoluble solids. In one pepper experiment, two other treatments were performed: WSA and sealed atmosphere with around 85% RH. The WSA was obtained by placing no...

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“…An increase in enzymatic activity upon maturity has been demonstrated in tomatoes (Hills et al, 1947)) cherries ( Al-Delaimy et al, 1966)) oranges (Rouse et al, 1962), and persimmons (Nakayama et al, 1966).…”

Section: Pectin Methyl Esterase Activity In Southern Peas (Vigna Sinementioning

confidence: 93%

Pectin Methyl Esterase Activity in Southern Peas (Vigna sinensis)

Collins

1970

Journal of Food Science

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SUMMARY: Pectin methyl esterase (PME) activity was investigated in vitro in Southern peas (Vigna sinensis). Experiments were conducted to determine the effect of NaCl concentration, pH, temperature, maturity, frozen storage and rinsing the peas on PME activity. The optimum salt level for maximum PME activity in the Purple Hull Pink Eye (PHPE) and Princess Ann (PA) varieties was ascertained to be 0.25 M. The pH optima were: PHPE, 8.5; and PA, 7.5 to 8. The remaining studies were made using peas of the PHPE variety which were harvested at 3 stages of maturity. Maximum enzymatic activity occurred at 50°–60°C. Partial inactivation occurred at 65°C. The mean Q10 was 1.35 over the range of 30°–50°C. PME activity was dependent upon the maturity of the peas. The most immature peas had an activity level about 2.5 times that found in the most mature peas. Peas subjected to frozen storage had a higher activity than the fresh peas; the increased activity was more pronounced in the more mature peas. Rinsing the peas removed significant amounts of the enzyme. A greater proportion of PME was removed from the more immature peas than from the more mature ones. With the immature, frozen peas PME activity was reduced 22.7% by rinsing; whereas, in the fresh counterpart the reduction was 11.1%. The rinse water from frozen peas contained more PME activity than did rinse water from fresh peas. Also, the activity in rinse water from the most immature peas was about 2.7 times that from the most mature ones. Upon standing, PME activity in the slurries prepared from frozen peas continued to increase up to 3–4 hr.

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Seasonal Changes Occurring in the Pectinesterase Activity and Pectic Constituents of the Component Parts of Citrus Fruits.

Cited by 37 publications

References 3 publications

Citrus Tissue Extracts Affect Juice Cloud Stability

Citrus Tissue Extracts Affect Juice Cloud Stability

Mode of Action of Plastic Film in Extending Life of Lemon and Bell Pepper Fruits by Alleviation of Water Stress

Pectin Methyl Esterase Activity in Southern Peas (Vigna sinensis)

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