كليدواژه :
انار (Punica granatum) , انبارماني , زمان برداشت , كيفيت پس از برداشت , ميوه
چكيده فارسي :
اطلاعات محدودي در زمينه جنبه‌هاي قبل از برداشت كه مي‌تواند فيزيولوژي پس از برداشت ميوه انار (Punica granatum L.) را تحت تأثير قرار دهد وجود دارد. هدف آزمايش حاضر، تعيين تغييرات شاخص‌هاي كيفي ميوه انار در ناحيه باغملك (استان خوزستان، جنوب غربي ايران) تحت تأثير مرحله بلوغ در زمان برداشت و مدت انبارماني بود. ميوه‌هاي انار رقم ملس پوست زرد در سه زمان برداشت (بيست و سوم شهريورماه، هفتم مهرماه و بيست و يكم مهرماه 1390) برداشت شده و به مدت 40 و 80 روز در دماي 7+ درجه سانتي‌گراد نگهداري گرديد. در هر مرحله برداشت و يا پس از 40 يا 80 روز انبارماني، برخي شاخص‌هاي فيزيكي (رنگ سطحي، پوسيدگي و چروكيدگي) و بيوشيميايي (اسكوربيك اسيد، مواد جامد محلول، اسيديته قابل تيتراسيون، pH، شاخص آنتوسيانين و شاخص‌هاي رنگ قهوه‌اي آب‌ميوه) اندازه‌گيري شدند. نتايج نشان دادند بدون در نظر گرفتن دوره انبارماني، ميوه‌هاي انار در ميزان غلظت مواد جامد محلول، اسيديته قابل تيتراسيون، pH و شاخص آنتوسيانين در آب‌ميوه تفاوت معني‌داري داشتند. برهمكنش اثرهاي زمان برداشت و مدت انبارماني (40 و 80 روز) بر چگالي، تغيير رنگ و چروكيدگي ميوه، ويتامين ث، پ‌هاش، اسيديته قابل تيتراسيون و رنگ آب‌ميوه (شاخص آنتوسيانين و شاخص رنگ قهوه‌اي) معني‌دار بود. نتايج نشان دادند برداشت ميوه‌هاي انار در زمان‌هاي مختلف، شاخص‌هاي كيفيت ظاهري و ويژگي‌هاي بيوشيميايي ميوه را تحت تأثير قرار داد و در زمان برداشت اول (بيست و سوم شهريورماه) موجب كاهش كيفيت ميوه گرديد ولي اين ميوه‌ها غيرقابل مصرف نبودند.
چكيده لاتين :
Background and Objectives
Preharvest and harvest conditions can affect quality and biochemical composition of fruit during storage. Pomegranate (Punica granatum L.) is a non-climactric fruit and there is no clear physiological index to determine the proper harvest time. Lack of standard maturity index results in prolonged period of picking pomegranate fruit within the season. The effects of different physical or chemical treatments on postharvest quality of pomegranate fruit have been investigated in many studies, but our knowledge on the pre-harvest and harvest aspects that influence pomegranate fruit postharvest physiology is scarce. The objective of the present experiment was to determine how qualitative indices of pomegranate fruit in ‘Bagmalek’ (Khuzestan, southwest of Iran) are affected by maturity stages at harvest and storage duration.
Materials and Methods
A factorial design including three harvesting times and three storage durations with three replications was used for statistical analysis. Fruits of ‘Malas Post Zard’ as an important pomegranate cultivar were harvested from a commercial orchard in ‘Bagmalek’ (150 Km Ahwaz, Khuzestan, southwest of Iran). Fruits were harvested at three harvest times at 14-day intervals (14 September, 29 September and 13 October 2011) and stored for 40 and 80 days at +7 oC. Some physical (weight, surface color, decay and shriveling) and biochemical characteristics (ascorbic acid, total soluble solids, titratable acidity, pH, anthocyanin index and browning index) were evaluated. The factors were evaluated at harvest time and after 40 and 80 days.
Results
Regardless of storage durations, pomegranate fruit showed significant variations in total soluble solids, titratable acidity, pH and anthocyanins. Interactions of the harvest time and storage duration (for 40 and 80 days) were significant on gravity, surface color changes, shriveling, ascorbic, acid, pH, titratable acidity and fruit juice pigments (anthocyanin index and browning index). Results showed that the period 29 September until 13 October 2011 and storage duration for 40 days are the best treatments to maintaining postharvest quality of ‘Malas Post Zard’ fruits in ‘Bagmalek’ (Khuzestan, Iran).
Discussion
Results showed that quantity and quality indices of the pomegranate could be improved through the selection of proper harvesting time. Harvest of pomegranate fruit at different maturity stages altered fruit appearance quality indices and biochemical characteristics under ‘Bagmalek’ geographic condition, and at early harvest time (14 September), it reduced fruit quality but did not make its consumption unacceptable. More research needs to assess the effect of different climatic parameters such as temperature and light intensity on the postharvest quality of pomegranate fruits in Khuzestan.
