INNOVATION IN FOOD SCIENCE AND TECHNOLOGY
Year:2010 | Volume:2 | Issue:1 (4)|Papers Count:9

As the date is one of the most important products in Iran, its the prominent role in nano technology for packaging and preserving of foods, has been surveyed in this regard. The microbial change of date in 2 temperatures (4°C and 25°C) with 2 different packages (polyethylene without nano composite and polyethylene covered by Silver nano composite and TiO2) has been scrutinized for 4 months. The result of this essay shows that making use of these nano ingredients in package of dates could reduce the microbial burden significantly. The activity of these nano particles led to obliterate micro organisms activities in these 2 conditions.Consequently the date with nano package can be preserved with out undesirable changes under ambient and refrigerator temperature for 4 months.

Different phospholipids namely, phosphatidyl ethanolamine, phosphatidyl choline and phosphatidic acid were used to evaluate their synergistic activities with Gallic Acid.Antioxidative activities of phospholipids were studied in tallow olein at 150 ° C at 0.01%, 0.04% and O.08% concentration, by measuring induction time. Rancimat apparatus was employed as a mean to evaluate the antioxidant activity and to determine the induction periods of the samples.The results showed that the addition of phosphatidyl ethanolamine exhibited synergistic activity with Gallic acid while phosphatidic acid showed such activity only at low concentration and phosphatidyl choline was inactive.

The effect of nisin Z (%0.2), and sodium benzoate (1.5 and 2.5%) on Caspian roach (Rutilus frisii kutum) fillet shelf life at 40C for a 16 days has been studied. . Microbial parameters (total viable count, psychrotrophic, and LAB), and chemical parameters (PV, and TVN) have been monitored during the storage time with a 4 days intervals. .The results showed that TVN and PV, in control samples, exceeded the allowed limit after 12 days, but in combined treated samples (nisin+sodium benzoate) they were acceptable until 16 days. The microbial count showed that the count of TVC, PTC and LAB in control samples were higher than those for treated with nisin and sodium benzoate. It exceeded the allowed limit after 16 days, but they were acceptable in combined treated samples after d 16 days. Results from chemical and microbial analysis showed that simultaneous use of sodium benzoate, and nisin Z could improve the shelf life of Caspian roach fillet packed in vacuum at 40c..

Probiotics are microorganisms with useful effects on human health especially in digestive system. Prebiotics are defined as non-digestible food ingredients that beneficially affect the growth of probiotics. The ability of prebiotic to increase the growth of good bacteria is well established. In the current experience, the probiotic growth in large colon has been stimulated and consequently increased, by an increase in growth and number of probiotics in the product.The aim of this study was to produce non-fermented symbiotic milk with natural taste and to evaluate the effect of prebiotics including Inulin, lactolose and galactooligosaccharides (respectively in 0.6, 0.4 and 1.6%) on probiotics count of La5 and Bb12 in cooled pasteurized milk. The probiotic cultures (count: 109 CFU/mL, dosage: 0.01% v/v) and prebiotics were added to 2,5% fat milk in Pegah pasteurized milk processing line. The chemical properties of milk and the survival of La5 andBb12 were studied at 4 degrees centigrades during 10 days in. Because of the non-fermentative nature of the product, no increase in probiotics count was observed.

In the present study an investigation was done on the physiochemical and microbial properties of saffron during 12 months after harvesting. Saffron was harvested from Torbat Heidarieh (a city in Khorasan Province), stigmas were separated by workers and the samples were dried in sieve by an electrical heater (Spanish method) at 55oC for 45 minutes until they reached the desired moisture content (according to Saffron National Standard). Second sorting was done, and then the samples were packed in polyethylene films at 20-25 oC and stored in lab. Sampling was taken monthly and analyzed for physiochemical and microbial properties including: moisture content, aqueous extract, crocin, picrocrocin, saffranal, total count, coliform and mold count. All experiments were done according to saffron national standard method. Moisture content, aqueous extract, crocin, picrocrocin and total count decreased during storage; however saffranal showed an increasing trend. Analysis of data indicated that the largest variations during one year storage has occurred from the beginning of harvesting time (December) to 8 months after storage (July), and after that variations were not statistically different (P>0.05) .

Natural improvers could help improve the quality of loaf bread. Thus this investigation was carried out to determine the effects of raisin concentrate as an edible improver. First raisin concentrate (Bx=70) in to a bread dough was used in three levels: 2, 4 and 6 percent. The results chemical, rheological, organoleptic and microbial tests were statistically analysed by Complet Randomized Design (C.R.D) .The results of rheological experiments showed that raisin concentrate (level 4%) had a significant effect to improve the rheological properties of dough, on increase the dough stability and resistance coefficient of dough for designing extansograph.Raisin concentrate levels, did not affect the viscosity of dough. The Results of staling experiments showed that raisin concentrate in amounts of 4% and 6% had significant effect to postpone staling. The Results of Organoleptic test showed that adding raisin concentrate (4 and 6 percent) could improve colour, porosity, form, shape and taste. The last Microbial test showed that using the raisin concentrate prevented moulds in loaf bread.

Since banana contains high sugar content and such fruits are so sensitive to spoilage in warm weather, using microwave ovens to dry them might have positive effects on their thermal process. At this research banana slices have been prepared at 3 different thickness (3-5 and 10mm) and treated by 3 pretreatment methods (T1 pretreatment: chemical blanching by sodium bisulphate solution 1%, T2 pretreatment: first blanching by boiling water and then chemical blanching by sodium bisulphate solution 1% and T3 pretreatment: first blanching by boiling water and then chemical blanching by citric and ascorbic acid mixture (1:1) solution and an untreated sample as a control sample. After preparation, the samples were dried at a microwave oven by 3 different microwave power intensities (300, 500 and 700 w) to achieve final moisture content. And finally dried samples were evaluated in terms of: quality parameters such as: color, rehydration, sugar and vitamin C content, drying rate and time. The results showed that at treated samples drying time decreased compared with control samples but drying rate didn't follow specific procedure and microwave power increased along with the drying rate increased but drying time was decreased. Also with increase of thick slices, drying rate were increased and drying time were decreased. Pretreatments had effects on color, re hydration, vitamin C and sugar content.

Anthocyanins are natural and colourful compounds in fruit and vegetables. In this study, anthocyanins extraction from Barberry (Berberis vulgaris) by ultrasound process at the selected temperatures (30, 40 and 50°C) and extraction times (10, 20 and 30 minuets) with two solvents (1.5 M HCl–95% ethanol) was done. Then, the concentration of the main anthocyanin in Barberry Cyanidin-3-glycoside was measured through pH differential method. Results showed that the most amount of extracted anthocyanins by Ultrasound extraction are at 50°C with extraction time 20 minutes. Under these conditions 188.58 mg of antocyanins from 100 ml of extract could be obtained. Natural colour was obtained from Barberry extraction with the brix of 60 and could be used in products, such as sweats, confectionary cream, ice cream and those product which must not further be exposed to high temperatures in their production. The outlook for the use of these colours in food sciences and technology seems to be promising due to the advances in non-heating processes, the importance of using natural colours in food product, and the positive effects of anthocyanins on health.