Author/Authors :
Nazoori, Fatemeh Department Horticulture Sciences - Vali-e-Asr University of Rafsanjan - Rafsanjan, Iran , Mirdehghan, Hossein Department Horticulture Sciences - Vali-e-Asr University of Rafsanjan - Rafsanjan, Iran , Shafei, Reyhaneh Department Horticulture Sciences - Vali-e-Asr University of Rafsanjan - Rafsanjan, Iran
Abstract :
Introduction: Due to its taste and nutritional properties, pistachio (Pistacia vera) is one of the most popular nuts in the world. One of the problems regarding the storage of fresh pistachios is hull browning. The phenomenon is the result of the formation of complex compounds and
colored polymers caused by enzyme reactions, which damage the texture,
aroma, taste and even the appearance of the fruit.
Materials and Methods: A study was conducted to investigate the
effects of citric acid (0, 1, 1.5 and 2%) and ascorbic acid (0 ,15, 25 and 35
ppm), as well as two types of polyethylene (LDPE) and polystyrene
coatings on the shelf life (day zero, 25 and 45) of Ahmad Aghaei pistachio
cultivar. The samples were prepared from a pistachio orchard located in
gardens in the area of Hozdagh in Kerman province. This experiment was
performed with three factors in a factorial design based on a completely
random design. Each value is the average of four replications (200-gr in
each replicate). Sources of variation were treatment (Ascorbic and Citric
acid), polymer coatings (polyethylene and polystyrene) and storage period
(0, 25 and 45). Results: The results indicated significant effects of the treatments,
polymer coatings and storage periods on some quantitative and qualitative
characteristics of the pistachios. Slight weight loss during storage was
observed in samples which were higher in polyethylene (0.45%) coatings
compared to polystyrene (0.22%). Treatments did not have a significant
effect on the pistachio firmness as compared with the effect of shelf life and
coating. The hull firmness decreased (30.5%) during storage, but it first
decreased and then increased in the kernel. In addition, the samples in the
polystyrene coatings had more rigidity (3.5%) than the pistachios in the
polyethylene package. In terms of browning, the appearance of the
pistachios in the packaging of polystyrene coatings was more desirable than
that of polyethylene coatings
Conclusion: In general, weight loss, firmness, apparent quality, and color indices were better in polystyrene coatings than polyethylene ones.
Keywords :
Ascorbic Acid , Citric Acid , Polyethylene and Polystyrene , Polymer
