Controlled atmosphere storage and aroma volatile production

Abstract

Purpose of the review: The techniques and principles of controlled atmosphere (C A) storage have been well explored for many frui ts and vegetables, especially for temperate zone fruits, wi th emphasis on supplying the consumer with “fresh” fruit for as mu ch of t he year as possible. It is now recognised that commercial appl ication of CA storage benefits retention of visual quality (appearance) t he most, followed by firmness retention, while the l owest benefit is retention of flavour, especially the aroma co mponent s of flavour. With the increasing ability of the industry to sati sfy appearance and firmness demands in the marketplace, increasing market atte ntion is being placed on the a roma properties of the fruit or vegetable. The refore, this review focuses on the infl uence of C A storage on product aroma production. Findings: There is a considerable amount of information on the identification of the major volatile components in the aroma of sev eral fruits. However, as in any relatively new field, there are subst antial qualitative differences in the volatile compositi on reported by differ ent research groups. Recently, more emphasis has been put on going beyond mere identification of the volatile com posi tion and to understanding the changes in volatile composition. This will positively affect not only CA storage techniques but al so our understanding of the physiology behind ripening and storage. L imitations/implications: Production and storage practices are subject to increasi ng scrutiny by consumers and researchers since m ore sensitive instrumental analysis equipment and techniques now m ake it possible to describe the influence of storage practices on vol atile production and aroma of the product. Nevertheless, due to the substantial qualitative di fferences in volatile composi tion i t is still difficult to compare results from different groups. Furthermore, the balance between the different volatiles is a very prec ise sci ence, with similar or even the same volatiles being important i n very different types of fruit, as wel l as different levels found i n different regions, cultivars and years. Thus, caution is required when using t his knowledge to adjust storag e conditions. Direct ions for future research: Identification of the volatile composition of fresh and stored fruit and understanding the changes in storage is f ar from complete. More research in the field is definitely needed and will undoubtedly im prove not only CA storage t echniques but also the understanding of the physiology behind ripeni ng and storage in general. C onsidering aroma-active compoun ds rather than all volatiles will be much more meaningful to the quality of the fruit. Keyw ords: Volatiles; controlled atmosphere; ethylene; aroma; flavour