Nasser Sedaghat; Ghodsieh Moradi; Sara Khoshnoudi; Arash Koocheki
Abstract
Introduction:Pistachio (Pistaciavera L.) is a tasty nuts and a good source of nutrients. During the last decade, the worldwide trades of pistachio have increasing trend, likely reflecting on the increase in consumers demand for this nuts. The high oil and essential fatty acid contents of the pistachio ...
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Introduction:Pistachio (Pistaciavera L.) is a tasty nuts and a good source of nutrients. During the last decade, the worldwide trades of pistachio have increasing trend, likely reflecting on the increase in consumers demand for this nuts. The high oil and essential fatty acid contents of the pistachio kernel is important from a nutritional point of view. However, high unsaturated fatty acids content makes pistachio nuts susceptible to oxidation and consequently off-flavors and off-aromas during storage.Mold growth and the production of aflatoxins is another food-safety concern about pistachio nuts. Lipid oxidation and fungal growth can be controlledby using an appropriateatmosphere in packaging.Therefore, the main objectives of this study were to determine the effect of Modified Atmosphere(MA) compared with Vacuum and Air condition packaging on physicochemical, microbialandsensory properties of raw dried Pistachio nuts (ohadi variety) in an accelerated storage conditions at 30±2°C and 50°C for 12 weeks. Material and methods: The pistachio nuts were treated with 3 different system packaging, these treatment includes modified atmosphere packaging (MAP at 88% N2; 10% CO2 and 2% O2), vacuum packaging and air condition packaging. The pistachio nuts were packed in five-layerpouches (2 PE+ 2 PA+1 glue :80 microns)and stored in triplicate at 30°C and 50°C for12 weeksand they were sampled every four weeks. Oil from pistachio kernels for peroxide, and fatty acid assay were extracted by cold extraction and n-hexane was used as extraction solvent. Peroxide value (Meq.kg-1) of the extracted oil was determined by spectroscopic absorbance reading at 500 nm. Free fatty acids (%), as oleic acid percentages in oil samples, were determined using the titration method. Moisture content (%) was determined by drying 5 g of ground kernels at 103±2 °C until constant weight. The mouldcontent (log CFU/g) of pistachios were performed according to the Iran standard method. The textural analysis of the pistachio nuts were performed using cylinderprobe (diameter: 20 mm) at test speed 50 mm/min and deformation of 4 mm for samples. Fracture force (N) and hardness (N) parameters were measured to evaluate textural properties ofpistachio nuts samples.Sensory evaluation was carried out by a 20 member trained panel (10 females and 10 males). Sensory attributes evaluated included color, firmness, rancidity and overall acceptability on 5 point hedonic scale, whit 5 for excellent and 1 for very dislike. Analysis of variance (ANOVA) was carried out using the least significance difference(LSD) test (p
Elmira Haghighi; Massoumeh Mehraban Sangatash; Seyed Ali Mortazavi; Mahboubeh Sarabi; Reyhaneh Noorbakhsh; Mohammad Armin
Abstract
The aim of this study was to investigate the mold contamination of main raisins varieties produced in Khorasan Razavi Province with aflatoxin-producing fungi and determine amount of aflatoxins. For this purpose 50 samples were collected from different markets in Kashmar, Khalil abad, Bardaskan, Mashhad ...
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The aim of this study was to investigate the mold contamination of main raisins varieties produced in Khorasan Razavi Province with aflatoxin-producing fungi and determine amount of aflatoxins. For this purpose 50 samples were collected from different markets in Kashmar, Khalil abad, Bardaskan, Mashhad and Quchan (10 samples from each city). The result showed that from 50 raisin samples, 44 samples (88%) were contaminated with fungi. The lowest and highest level of fungal contamination were observed in Quchan and Kashmar, respectively. Aflatoxigenic potential of fungi that isolated from contaminated samples were evaluated using Coconut Agar Medium and under UV light (365 nm). It is observed that 29 samples (65.9%) had Aflatoxigenic fungi. The presence of aflatoxin was confirmed by high pressure liquid chromatography. No sample had greater AFB1 levels than the maximum allowed levels (5 ng/g) in raisins accepted by ISIRI (Institute of Standards and Industrial Research of Iran). Although the amount of AFB1 in raisin varieties produced in Khorasan Razavi Province, does not appear to create a serious public health problem at present, because of Percapita consumption of raisins in Iran (22 kg/year) it is necessary to consider it as a serious health problem.
