Abstract
Quality of horticultural produce and products implies suitability for a particular purpose, or the degree to which certain set standards are met. Aspects of produce quality may encompass sensory properties (appearance, texture, taste and aroma), nutritive values, chemical constituents, mechanical properties, functional properties and defects (Abbott, 1999). Fruit and vegetable production, being part of a larger biological system, is prone to a high degree of variability as factors such as climate, soils, crop management, and genetics all play a role in quality determination. Quality standards and testing methods have been developed for most commercial crops to help ensure consumers receive produce of a suitable standard. These quality standards can range from basic grading for removal of damaged produce and for size, shape, weight and overall appearance, to analytical testing for compositional factors such as acidity, volatiles, dry matter, starch and sugars, toxins, vitamins and minerals, and others. With increasing competition globally within the horticultural industry, and consumers growing interest in high quality, nutritious produce, compositional testing has become more widespread, both at a grower and postharvest level. While appearance is still vitally important in marketing and for consumer appeal at the point of sale, focus on other aspects of fruit and vegetable quality is becoming more prominent. These include not only organoleptic qualities of flavour and aroma, but also nutritional factors such as vitamin and minerals, fibre content and levels of phytoactive compounds such as antioxidants. Compositional quality also encompasses food safety and shelf life concerns such as the presence of nitrates in leafy greens, microbial contamination and naturally occurring toxins, with implications for human health and food-borne illness occurrence.