نشریه فرآوری و نگهداری مواد غذایی
سال پنجم شماره 1 (پیاپی 13، بهار و تابستان 1392)

Phoenix Dactylifera A collection of flowers in each inflorescence branches grown on a diet of dates in the series are drawn oval wooden sheath. In this study, the antimicrobial properties against pathogenic bacteria Phoenix Dactylifera well dilution method (micro dilution) and disc diffusion and mold spoilage due to extract the disk diffusion method was studied. Tarvnh extract the bacteria Bacillus cereus, Salmonella, or general Shrshya, Staphylococcus aureus, and the fungus Trichoderma, Aspergillus niger and Aspergillus oryza produces inhibitory and germicidal effect that the greatest effect on Salmonella enterica bacteria with minimum inhibitory concentrations (MIC) against 5,000 minimum concentration of germicidal (MBC) against 5000, and the average diameter of the inhibition zone, mm) (5/13 that passes between the fungus and the greatest effect on Trichoderma mean percentage inhibition 25/83 percent, respectively. results showed that the extract Tarvnh bacterial growth can be productive and disease-causing food to prevent spoilage., so you can use it as a mix preservatives and flavors of natural food product can offer.

Biodegradable polysacharyd-based film was developed by incorporating pimpinella affinis essential oil (PAO) into methyle Cellulose (MC) at level of 0.5%, 1% and 1.5% v/v. Then, its antimicrobial activity tested against 7 bacteria include Staphylococcus aureus (PTCC 1431), Pseudomonas aeruginosa (PTCC 1151), Pseudomonas putida (PTCC 1691), Esherichia coli (PTCC 3315), Listeria monocytogenes (PTCC 1163), Bacillus subtilis (PTCC 465) and Vibrio parahemoliticus Films containing PAO showed significant antibacterial activity both gram-positive and gram-negative strainsa. The Inhibitory zone in film disks were increased with concentration of pimpinella affinis oil in the polymer matrix (P<0.05). Based on results, methyl cellulose edible coating contain 1.5% pimpinella affinis essential oil was used for microbial assay hypophthalmic molitrix during cold storage (4°c) which could inhibit of total bacteria growth and pscychrophilic counts of fillet.

The aim of this study was to investigate the effect of simultaneous application of ultrasound and osmotic dehydration pretreatments on changes of color parameters as well as sensory evaluation during hot air drying. In this evaluation, pretreatments including ultrasound time at two levels (10 and 30 minutes), osmotic solution concentrations at two levels (50 and 70 Brix) and immersion time in osmotic solution at four levels (60, 120, 180 and 240 min) were applied on plums and then the samples were dried at 80°C temperature and 1.4 m/s air velocity. The results showed that with decreasing moisture content during drying, the samples lightness "L" and yellowness "b" is reduced while the redness "a" is increased. The simultaneous application of ultrasound and osmotic dehydration pretreatments led to a significant increase in "L" and "b" and a significant decrease in "a" compared to control samples. In addition, application of the pretreatments improved the other color indices (Total color change, Chroma index, Hue angel and browning index). Sensory evaluation results of the dried plums showed an improvement in terms of appearance, color, taste and overall acceptability of the samples pretreated with ultrasound and osmotic dehydration. Moreover, modeling the color parameters changes of the plums during drying was done through the models available in the literature as well as the models proposed in this study. Then, one of the proposed models was selected as the best model to predict color parameters changes of the plums under the selected experimental conditions.

In this study extract of olive leaf was added to butter samples at three concentrations, 0.05, 0.1 and 0.5% and after vacuum packaging, were kept in refrigerator for 90 days. Acid and peroxide value, microbial culture, polyphenol content of samples, Hardness, Oxidative stability, sensory characteristics of samples including flavor, textural and apparent characteristics of samples and DPPH radical scavenging assay of olive leaf extract were evaluated. Results showed that samples which contained olive leaf extract had lower microorganisms content, acid and peroxide value, hardness and also higher oxidative stability and polyphenol content than samples without extract. Acid value was increased during storage and extract enriched samples showed lower increase. Peroxide value and polyphenol content of samples were decreased during storage too Hardness of olive leaf extract enriched samples was lower than control. The growth of microorganisms in sample which contained 0.1% olive leaf extract was lower than other samples. DPPH radical scavenging assay proved that antioxidant activity of olive leaf extract is lower than quercetin. Sensory characteristics evaluation also showed that Acceptability of samples decreased significantly with an increase in concentration of extract.

The objective of this study was to produce fish protein hydrolysate (FPH) with the most antioxidant activity, by enzymatic hydrolysis from (Carassius carassius). The protein of crucian carp a low value fish was hydrolyzed by Alcalase 2.4L and the optimal hydrolysis parameters of strongest antioxidant capacity of peptides were obtained using response surface methodology (RSM) by the central rotatable composite design (CRCD). The combined effects of temperature, time and enzyme activity on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging capacity of FPH were well fitted to a quadric equation with using Design expert software. The mathematical model presented a plateau region with maximum Antioxidant activity (>58.22%) at the following critical values: temperature = 48.11⁰C, time = 151.27 min and enzyme activity = 64.43 Anson unit per kilogram protein. Results indicated that crucian carp protein hydrolysate has the potential to apply as a natural antioxidant in foods ingredient and pharmaceutical applications in the future.

In this research, microwave-assisted hydrodistillation (MD) with pretreatment ultrasound (US) 45 and 90 min of essential oils from fresh Aegle marmelos peel were used and the results were compared with those obtained by hydrodistillation technique (HD) in terms of extraction yield/efficiency, extraction time, chemical composition and quality of the essential oil. All experiments were performed with at least three replicates. They were done according to GLM method and LSD Test in the SAS software system. The values obtained for essential oil from Aegle marmelos were achieved 2.00±0.2% and 1.97±0.2% by MD with pretreatment US (45 and 90 min) and 2.02±0.2% by MW. By using GC-MS system the composition of extracted essential oils were identified. The major component of essential oils obtained by both methods was limonene. There is no significant effect on the yield of essential oil and quality of essential oils extracted by MD with pretreatment US as compared to MW method.