Sampling strategy and minimum sample size to judge correct determination of grape maturity

The key to a good estimate of fruit maturity is to collect a sample that is truly representative of the entire harvested unit (i.e., block of one variety, plot). It is important to recognize the high level of variability in fruit composition that exists within a vineyard and even within a single fruit cluster. The target of this research was to determine grape quality selecting a correct sampling strategy (part of cluster, bunch and whole vine) and minimum sample size according to vineyard variability. The results show less variability on part of bunches than whole vine and single bunch samples. Less amount of grape samples, over estimated primary and secondary metabolite levels. Finally the keys to accurate fruit assessment are to use appropriate sample collection methods, proper analytical equipment and careful sensory evaluation.