Ranjith K. Kalleda, Inyee Y. Han, Joe E. Toler, Feng Chen, Hyun J. Kim and Paul L. Dawson
Wild caught shrimp can have a shortened shelf life compared to farm raised shrimp due to handling and on-ship limitations. The loss of freshness in shrimp is partly due to autolytic reactions caused by endogenous enzymes such as polyphenol oxidase. The objective of this study was to determine the effect of sulfites combined with modified atmosphere packaging (MAP) on the shelf life of non-frozen shrimp. Fresh South Atlantic white shrimp were subjected to one of four treatments, no bisulfite rinse-air packaged, 1.25% bisulfite rinse-air packaged, 1.25% bisulfite rinse-MAP (60% CO2, 18% O2, 22% N2) and 1.25% bisulfite rinse-MAP (36% CO2, 64%N2). The quality and freshness of shrimp was measured by determining total aerobic bacterial populations, package gas headspace analysis, shrimp volatiles (GC-MS), meat pH, nucleotide degradation, and visual analysis. Fresh non-frozen shrimp treated with a combination of sulfites and MAP maintained the shelf life of fresh shrimp up to 10 days while shrimp in non-MAP without sulfite and non-MAP with sulfite developed black spots within 2 and 6 days, respectively. Both MAP treatments slowed bacterial growth while the MAP with high CO2 and with O2 was more effective in preventing off odors and nucleotide degeneration.
Zoran S. Ilić, Elazar Fallik, Maja Manojlović, Žarko Kevrešan and Jasna Mastilović
Quality of produce cannot be improved after harvest, only maintained. Postharvest handling depends on the specific conditions of production, season, method of handling, and distance to market. Under organic production, growers harvest and market their produce at or near the peak ripeness more commonly than in many conventional systems. Organic production often includes more specialty varieties whose shelf life and shipping traits are reduced or even inherently poor. Harvesting and handling techniques that minimize injury to the commodity, as well as increased care with field and packinghouse sanitation, (chlorine, ozone, calcium hypochlorite, sodium hypochlorite and chlorine dioxide, acetic acid, peroxyacetic acid, vinegar, ethyl alcohol, hydrogen peroxide, etc.) during postharvest processes are vital components of a postharvest management plan for organic products. Sodium carbonate, sodium bicarbonate, and physical treatments such as heat treatments (as hot water treatment or dips, short hot water rinsing and brushing or hot air) can significantly lower the disease pressure on the harvested commodities. These sanitation practices are very easy to implement in the organic food production chain. They start in the field and continue during harvesting, sorting, packing, and transportation and continue even in the consumer’s home. All those treatments reduce rot development, provide quarantine security, and preserve fruit quality during cold storage and shelf life. In addition, the use chitosan, propolis, methyl jasmonate, essential oils, carnuba wax, biocontrol agents and modified atmosphere packaging can also reduce decay development during prolonged storage. All these treatments can be applied alone or in combination with each other in order to improve decay control after harvest and provide a healthy and safe product to the consumer. The aim of this chapter is to shed more light on the latest information on permitted treatments for organic products and on the possible mode-of-action of these treatments. This chapter summarizes technologies developed over the past five years that explore special physical treatments applied either directly, or in combination with other means to control rot development and insect infestation on fresh produce.
Influence of harvest date and storage conditions on the content of chlorophyll pigments in pear peels
During each season, pears were harvested on three dates at four-day intervals. The fruit was stored for 150 days in temperatures of 0-0.5°C in common cold storage (NA - normal atmosphere) and also in controlled atmospheres (CA) of different gaseous content: 0.8% CO2 + 2% O2, 2% CO2 + 2% O2 and 3% CO2 + 3% O2. After removing the pears from storage they were additionally stored for seven days in a temperature of 17°C - simulated shelf life. The content of chlorophyll pigments (chlorophyll a + b) was determined after each harvest date, storage time and simulated shelf life. Based on the results, I concluded that the a + b chlorophyll content in the peel of both pear cultivars significantly decreased along with the subsequent harvest date. In addition, the storage conditions had a significant influence on the studied factor. Compared to the normal atmosphere, the controlled atmosphere conditions were more efficient in slowing the yellowing of the fruit due to reduced chlorophyll degradation. The atmosphere consisting of 3% CO2 + 3% O2 or 2% CO2 + 2% O2 was more favourable for the higher content of chlorophyll a + b in the peel of ‘Conference’ pears than 0.8% CO2 + 2% O2. In the case of ‘Concorde’ pears, the influence of particular compositions of CA on the content of chlorophyll a + b changed over the years.
Ahmed Ezzat, Amin Ammar, Zoltán Szabó, József Nyéki and Imre J. Holb
The aim of this study was to investigate the effect of methyl jasmonate and salicylic acid on 12 quality parameters of apricot fruit in treatments of cold storage (1°C for 7, 14 and 21 days) and shelf-life (4 and 8 days at 25°C after a 21-day cold storage treatment). Fruit quality parameters included 6 physico-chemical characteristics (weight loss, fruit firmness, total soluble solids, acidity, total soluble solids/acidity ratio and juice pH) and 6 sensory properties (skin and flesh colour, texture, taste, visual appearance and overall acceptability). Among physico-chemical characteristics, applications of 0.2 mmol/L methyl jasmonate and 2 mmol/L salicylic acid significantly reduced fruit weight loss, fruit softening and juice pH and maintained soluble solid content and acidity over the whole storage period. Among sensory properties, all parameters were generally increased by methyl jasmonate and salicylic acid treatments compared to water-treated control and the water-treated fruits showed the lowest scores below the acceptability limit except for skin colour. In conclusion, our results suggest using methyl jasmonate and/or salicylic acid to enhance and prolong the storability of apricot fruits during both cold storage and shelf-life period.
Anna Rizzolo, Maristella Vanoli, Giulia Bianchi, Angelo Zanella, Maurizio Grassi, Alessandro Torricelli and Lorenzo Spinelli
‘Braeburn’ apples from three harvests after 6-month storage in controlled atmosphere were measured at 670 nm by time-resolved reflectance spectroscopy (TRS), ranked on decreasing μa670 (increasing maturity), classified as less (LeM), medium and more mature (MoM), randomised into three batches per harvest and analysed after 1, 8 and 14 days of shelf life. LeM and MoM apples were measured in the 630-900 nm range by TRS, and analysed for sensory profile (firm, crispy, juicy, mealy) and pulp mechanical characteristics (firmness, stiffness, energy-to-rupture). All data were processed by Principal Component Analysis (PCA). According to sensory intensity scores, fruits were either divided into five classes (very low – VL; low – L; medium – M; high – H; very high – VH) separately for every attribute, or clustered into four groups, each one representing a specific sensory profile. The absorption spectra showed a maximum at 670 nm (chlorophyll-a) and μa670 was higher in the VH class for firm, crispy and juicy and in the VL and L classes for mealy. The scattering spectra had a decreasing trend with the wavelength increase, and μs’ values were lower in the VH class for firm and crispy, and higher in the VH class for mealy and in the VL ones for juicy. PCA underlined that μs’ values were negatively related to firmness and μa670, and that μa690, μa730, μa830, μa850 and μa900 were opposed to mealiness. PC scores differed among the four sensory profiles and increased from VL to VH classes for firmness, crispiness and juiciness and from VH to VL classes for mealiness.
The American cranberry (Vaccinium macrocarpon Ait.) is a promising perspective and marketable crop both in Latvia and foreign markets, but an important problem is fruit rot in storage. The aim of the study was to investigate the incidence of cranberry fruit rot in storage from fruit collected in different locations in Latvia. In 2007-2011, two hundred sound berries (total 1200) were randomly collected by hand along a diagonal from six different cranberry plantations from locations all over Latvia in every year. Berries were kept in plastic polyethylene (PE-LD 04) bags for four months, refrigerated at +7 °C, 83% relative humidity. At the end of each month, berries were evaluated and rotten berries were separated from the sound ones. Over the period of 2007-2011, the optimal time for cranberry storage was two months, when losses due to fruit rot reached up to 18-21%. The incidence of storage rot at the end of storage period after four months (February) reached 50-88%. The hot and rainy summer of 2010 significantly reduced the quality of fruit in storage, and spoilage reached on the average 88% (74-100%) of berries in the plantations. The incidence of fruit rot varied among the surveyed cranberry growing sites. Storage rot is a problem in cranberry samples from all inspected plantations in Latvia and in the future, the incidence of fruit rot is expected to increase, because the greatest part of growers believe that American cranberries can grow in the same way as wild cranberries, without fertilisation and pesticide use
Grafting of vegetable seedlings is a unique horticultural technology, practised for more than 50 years, to overcome problems associated with intensive cultivation on limited arable land. Grafting vegetables can protect against soil-borne diseases and nematodes, against abiotic stresses such as high/low temperatures, salinity, drought or excessive soil-water content, and against elevated soil concentrations of heavy metals and organic pollutants. In addition, the grafted plant takes up water and nutrients from the soil more efficiently and retains its vitality for longer periods during the growing season. However, rootstock/scion combinations may affect and alter the final size, yield, and quality of fruits from grafted plants, both immediately postharvest and during prolonged storage. These alterations may be attributed in part to differing production environments and methods, the type of rootstock/scion combinations used, and harvest date. The aim of this paper is to review the most recent literature on the effects of grafting on postharvest quality of fruits/vegetables: tomato, watermelon, melon, eggplant, cucumber and pepper. The review will conclude by identifying several prospects for future research aimed at improving the quality of grafted fruit/vegetable products.
Elazar Fallik, Avital Bar-Yosef, Sharon Alkalai-Tuvia, Zion Aharon, Yaacov Perzelan, Zoran Ilić and Susan Lurie
The goal of this three-year study was to develop a quarantine-like treatment for two commercial sweet pepper (Capsicum annuum L.) cultivars, based on physical treatments and packaging materials, and to understand, in part, the chilling resistance-mode-of-action.
This research has revealed that individual shrink packaging following prestorage-HWRB treatment, significantly reduced chilling injuries and chilling severity, as shown by very low percentage of CI and a very low CI index, while maintaining a good overall quality (less decay incidence and weight loss) after 21 d at 1.5°C plus 3 d at 20°C (sea transport to USA and Japan from Israel + marketing simulation).
The chilling injury reduction is mainly due to a significant water loss reduction by the shrink film, while HWRB treatment contributed mainly to a significant decay reduction, and to some degree of inhibition of chilling development. Cultivar ‘Selika’ was found less susceptible to chilling then cultivar ‘7158’.