Factors Affecting the Postharvest Quality of Fruits
FARHANAMEHRAJ ALLAI1, DARAKSHAN MAJEED2', KHALID GUL3, SHAHNAZ PARVEEN2, and ABIDA JABEEN1
'Department of Food Technology, Islamic University of Science and Technology, Awantipora 192122, India
2Department of Horticulture, SKUAST-K, Wadura 193201, India
institute of Agriculture and Lite Sciences, Cyeongsang National University, Jinju 660701, South Korea
Fruits provide nutritional security and help growers to generate income. In order to get good quality produce good agricultural practices should be followed right from the start. Orchards should be monitored for regular water- supply, fertilizer applications, crop management, outbreaks of diseases and other environmental factors that govern the quality of fruits. Quality of fruits depends to a greater extent on the ripening and storage conditions of the fruits. There are both external and internal quality attributes that are responsible for obtaining good quality fruit. A grower should be well equipped with the latest technological know-how in order to face challenges in using technologies for obtaining high-class produce. However, there are other factors that are also responsible for the ripening disorders of the fruits. It has been observed that preharvest factors to a greater extent influence the postharvest losses as growers are not aware of the facts about postharvest biology of their produce. Therefore, efforts should be taken to make the growers understand the importance and effects of preharvest factors which control the quality of the produce.
Quality is the degree of excellence of a product. It is an important tool that determines the competitive power of fruits in the market. Different consumers perceive quality differently. Nowadays consumers have become very concerned about the quality of the produce they consume and generally consider color, firmness, and overall appearance of fruits as quality. Consumers consider fruits of good quality if their appearance good with attractive color and with good nutritive valve, whereas growers consider the fruit of good quality having a good texture, bigger in size, good appearance, and freeness from defects. Nutritive value of fruits to a greater extent depends upon the nutrition of plants. Plant nutrition plays an important role in fruit quality as well as storage stability. Quality parameters, such as firmness, color, aroma are the factors that have a great influence on the consumer acceptability of the produce. Other organoleptic properties like texture, juiciness, and crispiness are all quality factors that are also appreciated by consumers. These overall quality factors detennine the acceptability of fruit in the market (Vazquez-Araujо et al., 2010). There is now increasing appreciation that nutritional components like vitamins, minerals, antioxidants should be included in quality. Various studies have shown that fruits provide protection against various diseases like heart ailments, cancer, etc. (Dragsted et al., 1993; Anderson et al., 2000). Quality means different to different people. The degree of excellence of a produce is quality. Quality may be also defined as “fitness for purpose.” Some may perceive it as color, some texture, some flavor, or appearance. To the packers, it means ease of handling, uniformity of size, freedom from bruises, and pathogens (Arparia, 1994). Various factors such as are responsible for such quality factors before harvest. Even if the optimal conditions are the same there are big differences in the quality of produce, such as appearance color, etc. (Kays, 1999). There are various intrinsic and extrinsic factors that are responsible for quality attributes of fruits (Jongen, 2000). Poor crop management and field sanitation lead to drastic changes in terms of quality attributes by latent infections not only at harvest but also in the later stages of storage (Tyagi et al., 2017).
Quality attributes are affected not only by postharvest factors but preharvest factors also play an important role in maintaining the quality. Quality of the fruits after harvest depends on the ability of a farmer to manage the frequency of control of insects and pests or the use of hormones in the fields, management of cultural practices, and other factors, such as environment, temperature, rainfall, etc. There are various other preharvest factors which affect the quality of fruits or other horticultural crops like climatic conditions, genetic factors, pruning and thinning, irrigation, season and time, fertilizer application, and maturity stage.
Light and temperature play a vital role in altering the chemical composition of fruits (Seung and Kader, 2000). There are several environmental factors, like temperature, wind, rainfall, frost, which may directly or indirectly deteriorate the crops. Due to high rainfall, incidence of pathogens is high and frost may also lead in the scarring of fruits or may lead to chill injury. Temperature plays a vital role in either delaying or hastening the fruit quality. Temperature, light, and water affect the flavor of the fruits to a greater extent than any other factor. Both temperature and light help the fruits in attaining the overall eating quality of the produce (Kays, 1999). In some trees utilization of light is responsible for the productivity and quality of fruits (Tustin et al., 2001). The more leaf surface exposed to light more assimilation of the carbohydrates within the fruit occurs (Seleznyova et al., 2003). The canopy of the fruit-bearing branch and the position of the fruit also affects the rate of photosynthesis in the trees as the proper positions of the canopy enhance photosynthetic capacity in leaves, fruit, etc. (Hollinger, 1996). The bioactive components are affected directly by environmental factors which provide a prerequisite for the formation of precursors for the synthesis of these components (Hewett, 2006). Poor fruit structure occurs due to nonavailability of carbohydrates which further is responsible for yield loss (Measham et al., 2012). The temperate fruits that require a warm growing season and a dormant winter season followed by the spring temperature (Howell and Perry, 1990). For the development and growth of the buds, warm temperature and good light levels are needed to support the photosynthesis. (Looney et al., 1996). Cool weather and prolonged rainy season are detrimental and result in the reduced fruit set when blossom occurs. Severe damage to the fruits occurs if rainy season increases during the ripening period of fruits (James, 2011). It has also been reported that preharvest conditions also are responsible for the reduced fruit set and reduced firmness quality of fruits.
Different quality parameters like color, shape appearance, size, and weight are a measure of genetic factors that control the quality genetically. Different fruit varieties differ in quality parameters due to a difference in genetic makeup (Kumar and Kumar, 2007). A grower can select the variety or cultivar according to his own choice depending on the availability of the varieties and soil types and climatic conditions of that area (Hewett, 2006). Genetic factors are also responsible for increased firmness, resistance to different pathogens, and increased firmness of fruits (Scalzo and Mezzetti, 2010). Recent developments in plant breeding have shown to increase the disease resistance, increase in yield, winter and heat tolerance, and seedlessness of fruits (Clark, 2005).
Different cultural practices, like type of soil and manure, have a great influence on the nutrient supply to the plants and that of the fruit also (Kader, 2002). Deficiency in nutrient composition or water at the time of fruit set, flowering or before harvesting reduces the yield of fruits to a great extent. Seasonal changes, like prolonged rainfall during the growing season, alters the nutritional composition of the fruit and makes the fruits susceptible to various diseases during storage (Kader, 2000). Insufficient amount of minerals in the soil can lead to various physiological disorders in fruits, for example, bitter pit of apples and watermelons, cork spot of apples and pears, and a red blotch of lemons are also results of calcium deficiencies. Other disorders, such as lumping rind of citrus fruits, cracking of apricots, corking of apricots, pears, and apples, arise from the deficiency of Boron. Reduced fruit size and high total soluble solid content is a measure of high salinity of soil. Inadequate supply of nitrogen can lead to poor color, texture, and flavor of fruits (Ali et al., 2012). Calcium plays an important role in the structure formation of fruits and its deficiency can result in the early fruit set resulting in poor quality of fruits (Ferguson et al., 1999). Nitrogen is also an important component for the development of color, size, firmness, flavor, maturity, and Sugar content of fruit. Insufficient nitrogen may lead to the low flower bud formation in case of cherries that may further result in the formation of smaller fruits with intense color formation and early maturity (Flore and Lane, 1999) and, in turn, excessive nitrogen content may lead to less color formation and decreased firmness and delaying in maturity. Phosphorus is found to increase the firmness and size of the fruit (strawberries) and reduce the cull foimation. It also increases the fruit size and reduces the chances of decaying of fruits. Only the minerals present in the soil does not have any effect on the quality of fruit but the rootstock has a great effect on the quality like mineral uptake, yield, development of firmness in fruits, and their biochemical composition (Gon Calves et al., 2005). The interactions of the rootstock and scion affect the juice quality of citrus fruits and alter the titrable acidity, total soluble solid content, and fruit mass. Rootstock may also influence the accumulation of anthocyanins, polyphenols, vitamins, acids, and sugars in some fruits like cherries (Spinardi et ah, 2005). The yield and quality of volatile peel oil depend mainly on the rootstock (Arpaia, 1994).