پديد آورندگان :
زارعي، لولاو دانشگاه كردستان - دانشكده كشاورزي - گروه علوم و مهندسي باغباني، سنندج، ايران , كوشش صبا، محمود دانشگاه كردستان - دانشكده كشاورزي - گروه علوم و مهندسي باغباني، سنندج، ايران , وفايي، ياور دانشگاه كردستان - دانشكده كشاورزي - گروه علوم و مهندسي باغباني، سنندج، ايران
كليدواژه :
تركيبات زيست‌فعال , ليكوپن , سفتي , فعاليت آنزيمي
چكيده فارسي :
گوجه‌فرنگي يكي از سبزي‌هاي مورد علاقه و پرمصرف در جهان است كه ميوه آنسرشارازمواد معدني، ويتامين‌هاوتركيباتضد‌اكسايشيمي‌باشد، اما اين محصول با خاستگاه گرمسيري به دماي پايين حساس است كه محدوديت جدي در عرضه پس از برداشت محصول دارد. در اين آزمايش اثر تيمار دو هفته قبل از برداشت اسيد گاما-آمينوبوتيريك در سه سطح (صفر، 5 و 10 ميلي‌مولار) بر كيفيت پس از برداشت و سرمازدگي ميوه گوجه‌فرنگي رقم نيوتون در سال 1396 در دانشگاه كردستان مورد بررسي قرار گرفت. برداشت ميوه بعد از مرحله بلوغ فيزيولوژيك صورت گرفت. پس از برداشت ميوه، طي دوره انبارداري (در دماي 4 درجه سلسيوس و رطوبت نسبي 95-90 درصد) در روزهاي صفر، 5، 10، 15 و 20 برخي خصوصيات فيزيكي، زيست شيميايي و صدمه سرمازدگي مورد ارزيابي قرار گرفت. ميزان سرمازدگي ميوه شاهد در روز آخر 25 درصد مشاهده شد، در‌حالي‌كه در تيمار اسيد گاما-آمينوبوتيريك 10 ميلي‌مولار 33/8 درصد بود. تيمار برگي اسيد گاما-آمينوبوتيريك سبب كاهش از دست دادن وزن، حفظ سفتي و همچنين، حفظ ويتامين ث و اسيديته قابل تيتراسيون نسبت به تيمار شاهد گرديد. تيمار اسيد گاما-آمينوبوتيريك سبب بهبود ويژگي‌هاي كيفي و افزايش رنگيزه ليكوپن در گوجه‌فرنگي نسبت به ميوه‌هاي شاهد شد و خسارت سرمازدگي را به‌طور قابل توجهي كاهش داد.
چكيده لاتين :
Background and Objectives
Tomatoes are considered the favorite and most widely consumed vegetables in the world since their fruit is rich in minerals, vitamins and antioxidant compounds. Tomato fruit is harvested after physiological maturity at different color stages based on consumption type. Mature unripe tomato fruit could be stored for long time and be ripened according to market demand, but this tropical product is susceptible to low temperature, which imposes serious constraints in postharvest period and supply chains. Several techniques or chemical treatments have been used to decrease low temperature deleterious effects. Gamma-mino butyric acid (GABA), as an efficient tool, could increase plant resistance to chilling injury (CI) during postharvest life. This study was carried out to evaluate the effect of pre-harvest GABA spray on postharvest quality changes and chilling of tomato fruit during cold storage.
Materials and Methods
In this study, the effect of pre-harvest application of GABA at three concentrations (0, 5 and 10 mM) on postharvest quality and chilling of tomato cv. Newton was evaluated. The spray was carried out 2 weeks before harvest. Fruits were harvested after physiological maturity when the fruit color changed from pink to red. During storage period at 4 °C and 90-95% relative humidity, some fruit quality attributes such as weight loss, firmness, chilling injury of tomato fruit, soluble solid content (SSC), titratable acidity (TA) and fruit bioactive constituent were analyzed at days 0, 5, 10, 15 and 20.
Results
Chilling in control fruit was 25% at final assessment, while in 10 mM GABA treatment it was only 8.33% at the same time. GABA treatments decreased the rate of weight loss and retained fruit firmness during storage. Also, vitamin C and titratable acidity in GABA treatments were higher than those of untreated fruit. Fruit lycopene content increased during fruit storage in both treated and untreated fruit, but the value was greater in GABA treatments than the control. SSC increased during fruit storage, but it was greater in control than the treatments. While superoxide dismutase enzyme activity decreased in both treated and untreated fruit, the rate of decline in control fruit was greater than GABA treatments.
Discussion
Pre-harvest foliar application of GABA ameliorated chilling injury induced by cold storage, maintained quality properties of tomato fruit, and increased lycopene content. GABA treatments probably lessened deteriorate effect of low temperature through keeping fruit cell integrity and higher bioactive constituent levels.
