Consumer interest in the quality of vegetable products has increased in recent years. Regular consumption of vegetables has been linked to a reduction of some diseases, since vegetable is a source of an array of phytochemicals, which are appreciated for their beneficial health effects. Vegetable quality is a complex issue with different means depending to the target customer group. Quality has both a product- and a consumer-dependent dimension. From the first perspective, quality attributes are inherent in a product and can be objectively quantified, whereas a consumer orientation, which defines quality in terms of user satisfaction, is much less tangible and less quantifiable concept. This review will be focused only on product-oriented quality and objective criteria for its evaluation. Standard for quality assessment of fresh vegetables are established in Europe and North and Central America. However, they take into consideration mostly external quality attributes (e.g. size, shape, color, absence of defects and decay, critical concentrations of pesticides and nitrate), whereas very important internal quality attributes such as texture, flavor and health promoting compounds are not considered. Environmental conditions, crop management and physiological factors may modify the vegetable quality. The purpose of this paper is to review the recent literature dealing with the main pre-harvest factors that can modify the quality of vegetables and, in particular, the physical properties, flavor, and health–related compounds. First of all, the importance of the genotype and grafted plants selection, the optimization of the environmental conditions and the advantages and disadvantages of protected environments in comparison to open field cultivation concerning product quality will be outlined. Then, the effects of the optimization of agricultural practices, in particular water quantity and quality, mineral nutrition and growing systems (e.g. soilless culture), will be discussed. The review highlighted that vegetable quality is a product of the interaction of genetic, climatic, and cultural factors. Finding the best combinations of those factors to maximize vegetable quality according consumer demand will be a challenge. The use of novel cultural practices and development of new genetic lines to enhance the quality of vegetables are the main directions that research should take in the near future. Integrated quality production and management must be considered as a global target to reach.
Keywords: cultural practices, grafting, health-related compounds, vegetables