บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Use of calcium salts to delay postharvest senescence of fruit and vegetables

Strydom, Gerhardus Johannes.

Dissertation Abstracts International

1980

บทคัดย่อ

USE OF CALCIUM SALTS TO DELAY POSTHARVEST SENESCENCE OF FRUIT AND VEGETABLES.

This thesis reports on the effects of postharvest application of calcium on ripening and senescence of intact tomatoes, bananas, pears, mangoes, avocados, carrots, parsley, beans, Brussels sprouts and potatoes.

 Ripening of Rouge de Marmande and Day Dream tomatoes was inhibited when calcium content of the fruit was raised to greater than 40 mg/100 g fresh weight from an endogenous level of about 11 mg/100 g.

 Inhibition of ripening was not specific to calcium, as other divalent ions--manganese, cobalt, and magnesium--were as effective as calcium.  The monovalent ions--sodium and potassium--were relatively less effective.

 Calcium-treatment accelerated ripening of Cavendish bananas.  Acceleration of ripening was not specific to calcium but occurred as effectively with other divalent ions--magnesium, zinc, and barium.  Copper was even more effective than calcium in initiating ripening.

 Application of calcium by infiltration retarded all aspects of ripening of pears, mangoes and avocados.  The use of up to 12% calcium chloride solution had no adverse effect on the physical appearance of pears whereas use of more than 4% calcium chloride in the dip caused varying degrees of skin injury to mangoes and avocados.

 The ripening time of Williams Bon Chretien pears at 20(DEGREES)C was extended from about 10 days in control to about 15 days in fruit receiving about 8 mg calcium/100 g fresh weight.  Ripening of Kensington Pride mangoes was delayed by about a week over control fruit which ripened after about 2 weeks.

 With Fuerte avocados, an incorporation of up to 5 mg calcium/100 g into the flesh tissue achieved through infiltration with 2% calcium chloride solution depressed respiration and evolution of ethylene and delayed flesh softening.  In Hass avocado fruit, use of higher concentrations of calcium chloride were required to achieve the appropriate calcium uptake.

 For vegetables examined, calcium had no beneficial effect in terms of marked reduction in the rate of respiration or retardation of loss of visual quality.  Postharvest treatment with calcium to delay ripening of mangoes, pears, and avocados during transport and marketing at ambient temperatures seem to have potential commercial usage.