Comparison of Regular Atmospheric Storage versus Modified Atmospheric Packaging on Postharvest Quality of Organically Grown Lowbush and Half-Highbush Blueberries

Angela Koort,Ulvi Moor,Priit Põldma,Clive Kaiser,Marge Starast

doi:10.3390/su10113916

Abstract

The aim of the study was to determine the effect of modified atmosphere (MA) packages on the external quality of organically grown lowbush blueberry and half-highbush blueberry (’Northblue’) and the nutritional value of the fruits. Fruits were divided into plastic punnets and stored as follows: regular atmosphere (RA), punnets without packing; punnets sealed in a low-density polyethylene (LDPE, Estiko) bag; punnets sealed in an Xtend® blueberry bag (Stepac). Fruits were stored at 3 ± 1 °C. Compared to RA conditions, the Xtend® package prolonged the postharvest life for 15 days for lowbush and 9 days for half-highbush blueberries. Fruit dry matter (DM) and titratable acidity (TA) were higher in the Xtend® package. Fruit SSC decreased in the LDPE packages and increased in the Xtend® packages during storage. Based on the decreased soluble solids content (SSC) and titratable acidity (TA) ratio (SSC:TA) values during storage, it can be concluded that the taste of the fruits became sourer in all packages. Anthocyanin biosynthesis of lowbush blueberries was suppressed in MA, but this effect was not noticed for ‘Northblue’. Regarding fruit firmness, shrivelling, and decay, there were significant differences between the MA packages, but the genetic differences were more important: half-highbush blueberry fruits were firmer and less shrivelled.

Highlights

Interest in blueberries (Vaccinium spp.) is rising because of their health-promoting constituents, including flavonols, tannins, phenolic acids, and anthocyanins, which help to prevent cardiovascular diseases, cancer, and inflammation [1]
For the lowbush blueberry low-density polyethylene (LDPE), the packaging extended the postharvest life for only 22 days, which was similar to the regular atmosphere storage in punnets, whereas the Xtend® packaging resulted in a shelf-life of up to 37 days
The half-highbush blueberry (‘Northblue’) had a longer postharvest life compared to the lowbush blueberry in the LDPE film, which refers to the genetic difference of these two taxa and may suggest that the suitability of the film is species-specific

Summary

Introduction

Interest in blueberries (Vaccinium spp.) is rising because of their health-promoting constituents, including flavonols, tannins, phenolic acids, and anthocyanins, which help to prevent cardiovascular diseases, cancer, and inflammation [1]. Blueberries are sold in fresh, frozen, and processed forms, and additional research is needed to extend the postharvest life of fresh blueberries to further extend the marketing season and to reduce waste. The postharvest quality of blueberries is affected by diverse physical, physiological, and pathological processes and aspects of blueberry deterioration including decay, shrivelling, and softening [2]. Major causes of postharvest spoilage for blueberries are fungal decay and physiological changes [3]. Though, storing blueberries in a CO2-enriched atmosphere is an effective way of extending the postharvest life and inhibiting postharvest decay without fungicidal treatments [4]. Modified-atmosphere packaging has the potential to provide low O2/high CO2 regimes, but the packaging must maintain the appropriate atmospheric composition over a range of temperatures commonly encountered between harvest and consumption [5]

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Conclusion