Book excerpt: Food quality is becoming an ever-increasing important feature for consumers and it is well known that some food crops are perishable and have a very short shelf and storage life. An effective quality assurance system throughout the handling steps between harvest and retail display is essential to provide a consistently good quality supply of fresh food crops to the consumers and to protect the reputation of a given marketing label. Food manufacturing companies all over the world are incre- ingly focussing on quality aspect of food including minimally processed food to meet consumer demands for fresh-like and healthy food products. To investigate and control quality, one must be able to measure quality-related attributes. Quality of produce encompasses sensory attributes, nutritive values, chemical constituents, mechanical properties, functional properties and defects. Successful postharvest handling of crops requires careful coordination and integration of the various steps from harvest operations to consumer level in order to maintain the initial product quality. Maturity at harvest is one feature of quality of perishable products, it has great influence on their postharvest behavior during marketing. Safety assurance can be part of quality assurance and its focus on minimizing chemical and microbial contamination during production, harvesting, and postharvest handling of intact and fresh-cut of commodities. Essentially, electromagnetic (often optical) prop- ties relate to appearance, mechanical properties to texture, and chemical properties to flavor (taste and aroma).