Postharvest losses

S. rolfsii also causes storage rots in tubers that appear sound at harvest (Thompson, 1928). The fungus produces a silky white mold on which numerous spherical sclerotia appear (Snowdon, 1992). Postharvest losses can be controlled by low-temperature storage or, in the absence of refrigeration, through the use of prestorage fungicide dips (Thompson, 1928). 

Sclerotium rot is a serious tuber rot in the field and storage (McCarter and Kays, 1984), caused by S. rolfsii. The tubers display robust white to light brown mycelium with numerous spherical sclerotia. Postharvest losses can be largely prevented with low-temperature storage (Johnson, 1931 Thompson, 1928). 

Boxall, R.A. 1991. Postharvest losses to insects-a world overview. In Biodeterioration and Bio-degredation (H.W. Rossmore, ed.), pp. 160-175. Elsevier, Barking, UK. 

Postharvest losses can be estimated at more than 30% [148,149] and it could be reduced to a great extent by adequate drying of crops [150]. 

One of the prime goals of food processing or preservation is to convert perishable foods snch as fruits and vegetables into stabilized products that can be stored for extended periods of time to reduce their postharvest losses. Processing extends the availability of seasonal commodities, retaining their nutritive and esthetic values, and adds variety to the otherwise monotonous diet. It adds convenience to the products. In particular it has expanded the markets of fruit and vegetable products and ready-to-serve convenience foods all over the world, the per capita consumption of which has rapidly increased during the past two to three decades. 

Recent works show fruit and vegetable purees as good alternative edible materials. The use of these ingredients can also help reducing postharvest losses by using overripe fmits or those fraits that present lower quality and cannot be sold as first grade... 

FIGURE 1.2 Estimation of the postharvest losses and utilization of cereal grains in 2007. 

Ethoxyquin, a synthetic antioxidant, is not generally allowed for human consumption in foods, but it is being added to animal feed and to fruits as an antiscald agent (94,143). Ethoxyquin is also used in the spice industry to prevent carotenoid loss during postharvest handling. However, ethoxyquin-treated paprika is unacceptable for some markets and some consumers (129). Perfetti et al. (130) described a method for determination of ethoxyquin in paprika and chili powder. Ethoxyquin was extracted from the spice with hexane and partitioned into 0.3 N HC1. After adjusting the solution to pH 13-14, ethoxyquin was extracted into hexane, and the hexane layer was evaporated to dryness. An acetonitrile solution of the residue was then analyzed by reversed-phase HPLC, with detection at 254 nm. The mobile phase was water/acetonitrile with ammonium acetate buffer. Recoveries from samples fortified at 50, 100, and 200 ppm averaged 92%, with a coefficient of variation of 2.3%. The method was applied to a number of commercial samples of paprika and chili powder. Ethoxyquin was found in paprika samples at levels up to 63 ppm and in chili powder samples at levels up to 20 ppm. 

With the exception of 2,4-D and gibberellic acid treatments of a variety of citrus crops, where improved fruit set, reduced fruit drop, and the ability to delay harvesting without loss of fruit quality are recognized benefits, few applications have been developed for the use of hormone-type regulators in tropical fruits. Recent work has shown that gibberellic acid will delay postharvest ripenining and improve the quality of bananas and that napthaleneacetic acid treatment of oil palm to delay fruit abscission has increased both yield and oil content. 

Maalekuu, K., Elkind, Y., Leikin-Frenkel, A., Lurie, S., and Fallik, E. (2006). The relationship between water loss, lipid content, membrane integrity and LOX activity in ripe pepper fruit after storage. Postharvest Biol. Technol. 42, 248-255. 

A wide range of microorganisms (fungi, bacteria, viruses, and mycoplasms) mediate substantial losses to crop plants during both the production phase and postharvest period. While Jerusalem... 

The final word about risk-benefit is that the definitions of the risks and the benefits are not the same in all cases. The definition of benefit needs to be clear. For some countries, the benefit is reduced postharvest food losses. The value of this benefit can vary with the country involved. Different weights may be assigned if there is danger of severe food shortage versus simply an increase in the cost of the substance. Thus, the science and art of risk assessment are difficult because each step in the process is value laden. 

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