Document Type : Full Paper

Authors

• Mohammad Zarrinbal ¹
• Jaber Soleimani ²
• Hossein Fathi ¹
• Mehri Yousefi ¹

¹ Crop and Horticultural Science Research Department, East Azerbaijan Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Tabriz, Iran.

² Agricultural engineering Research Department, East Azerbaijan Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Tabriz, Iran.

Abstract

Keywords

• Apricot
• Harvesting time
• Packing
• Storage life

Main Subjects

• Fruit Science

Extended Abstract

Introduction

     The quality of apricot fruit can be affected by the stage of ripening and the duration of fruit storage. The most important factors effective on the fruit quality include fruit skin color, flesh firmness, aroma, and taste. Some issues such as high respiration and rapid ripening generally reduce duration of storage life. Therefore, it is very important to deliver fruit to the target markets immediately after harvesting. In order to earn more income from selling fresh apricot to regional and foreign markets, it is essential to standardize the ripening stage of the fruit, determine the appropriate time for harvesting, and recognize suitable fruit packing. These standards are different based on cultivar, environmental condition, and market demands. This study was performed to determine the appropriate time of harvesting and method of packing of two new apricot cultivars in favor of extending their storage life.

Material and Methods

    The fruit of two new apricot cultivars including 'Derakhshan' and 'Sahand 97' along with a commercial cultivar called 'Ordoubad 90' (as control) were harvested at three stages of fruit ripening based on the index of fruit’s skin color. The first fruit harvesting was performed at the growth stage of green background with yellowish spot, the second at yellow background with green spot, and third at yellow-orange background. Afterward, the harvested fruit was packed with the two methods (i.e., uncovered or polyethylene-covered packing), and it was then stored at 2˚C and 85% of RH for 0 (control), 7, 14, 21, and 28 days. After each period of storage, the fruit was evaluated for its quality characteristics, such as fruit taste, shriveling, gel breakdown and decay percentage. The other fruit characteristics including fruit weight, fruit firmness, total soluble solids, pH, and electrical conductivity of fruit extract were also measured.

Results and Discussion

    Cluster analysis showed that appropriate time of fruit harvesting was at yellow background with green spot, and appropriate method of packing was using polyethylene-covered packing; accordingly, both factors could extend the duration of apricot’s storage life. The appropriate time of fruit harvesting was concurrent with 72 d after full bloom or 841 growth degree days for 'Derakhshan', 98 d after full bloom or 1375 growth degree days for 'Sahand 97', and 92 d after full bloom or 1241 growth degree days for 'Ordoubad 90'. In this context, the fruit of 'Derakhshan' and 'Ordoubad 90' could be cold-stored with suitable quality for up to 14 and 28 days, respectively. However, the fruit of 'Sahand 97' had a remarkable storage life and it did not show any significant differences in harvest time and packing method at least during 28 days of cold storage. A delay in the time of harvesting and reduction in duration of cold-storage would lead to emerging some disorders such as fruit’s shriveling, gel breakdown, and decay percentage. The results of ANOVA showed a significant difference between cultivars in terms of fruit firmness, total soluble solids, pH, and electrical conductivity of fruit extract (P≤0.01). The fruit picked at the first harvest was firmer on the first days of harvesting compared to other rounds of harvesting. Delaying in fruit harvesting and shortening storage life could lead to fruit’s flesh firmness in both packing methods. In general, using a polyethylene-covered packing extended the duration of fruit storage life. Furthermore, fruit of all cultivars picked at the third stage of harvesting and stored for 28 d possessed higher total soluble solids, pH, and electrical conductivity. Besides, fruit of 'Sahand 97' and 'Derakhshan' showed the highest and lowest storage life, respectively. Moreover, our results suggested that ripened fruit had more respiration and ethylene production, resulted in providing some physiological and biochemical changes in fruits including fruit color change, texture softening, starch breakdown, sugar increase, acidity reduction, and changes in the flavor and taste of fruit. 

Conclusion  

    The results of this research showed that three factors, including the time of harvesting, method of packing, and type of cultivar, had a remarkable effect on quality and storage life of apricot’s fruit. Based on our findings, the appropriate time for fruit harvesting allocated to the time at which the color of fruit skin was almost yellow with green spots in background. In addition, the suitable method for fruit packing, in line with extending fruit storage life, was packing fruit in a polyethylene cover.