نوع مقاله : مقاله پژوهشی
نویسندگان
1 بخش زراعی و باغی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی آذربایجان شرقی، سازمان تحقیقات، آموزش و ترویج کشاورزی، AREEO، تبریز، ایران
2 بخش فنی و مهندسی کشاورزی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی آذربایجان شرقی، سازمان تحقیقات، آموزش و ترویج کشاورزی، تبریز، ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
To earn more income from fresh apricot market, it is important to consider the time of fruit harvesting and method of packing. This study was conducted to determine the most appropriate time of harvesting and method of packing of three apricot cultivars including 'Darakhshan', 'Sahand 97', and an economically well-known cultivar called ‘Ordubad 90' (as control). In the beginning, their fruit, based on the skin color index, was harvested at three fruit ripening stages (i.e., fruit skin color green background with yellow spots, yellow background with green spots, and yellow background with orange spots). After harvesting, the fruit was packed using two methods (uncoated packing and polyethylene-coated packing) and stored in a cold storage at 2°C and 85% of relative humidity (RH) for 0 (control), 7, 14, 21 and 28 days. In order to assess the quality of fruit at different periods of storage, the characteristics of fruit weight, texture firmness, total soluble solids, pH, and electrical conductivity of the fruit extract were investigated. Results revealed that not only harvesting at the second stage of fruit ripening (i.e. yellow skin color with green spots) was the most suitable time, but also packing apricot fruit with polyethylene was a suitable method for extending storage life of fruit. Furthermore, although the results of this work showed that the fruit quality of 'Darakhshan' and 'Ordubad 90' could be maintained at cold storage for up to 14 and 28 days, respectively, the fruit maintenance of 'Sahand 97' was greater than that in the above-mentioned cultivars. In addition, no significant difference was found between the three harvesting stages and packing methods for 'Sahand 97' in terms of storage life at least in 28-day period of storage life. Overall, some disorders such as skin wrinkling, flesh jelly formation, and fruit spoilage built up during the cold storage because of delaying in apricot fruit harvesting. During cold storage, fruit firmness declined, but total soluble solids, pH, and electrical conductivity (EC) of fruit rose. In conclusion, harvesting fruit at an appropriate time and packing in a suitable method could lead to improve apricot fruit at cold storage qualitatively and quantitatively.
کلیدواژه‌ها [English]
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.
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