JWSS - Journal of Water and Soil Science

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In order to determine the effects of emulsifiers (Lecithin, E471 and E472) and their levels (0, 0.25, 0.5, 0.75 and 1%) and also addition of fungal α-amylase (0, 5, 10 and 20 g/100 kg flour) on bread staling, a completely randomized experiment with factorial design and 3 replications was conducted. Bread staling was determined after 0, 24, 48 and 72 hours of storage. Correlation between variables was analyzed by simple and multivariate regression. Results indicated that addition of emulsifiers reduced the firmness of bread. E472 had the most and E471 had the least effect on bread firmness after 72 hours of storage. Addition of α-amylase reduced the bread firmness and this effect was less pronounced after 72 hours of storage. Correlation between variables based on the development of a model showed that in the first day of bread production, optimal levels of emulsifiers were 1%, 0.25% and 0.5% for Lecithin, E471 and E472, respectively. In case of simultaneous application of emulsifiers and enzyme, the optimal level of enzyme was 5 g/100 kg flour.

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The present experiment was aimed to evaluate the freezing tolerance of two cold tolerant (MCC426 and MCC252) and a cold susceptible (MCC505) chickpea genotypes. The study was carried out in a split-plot factorial design with three replications. Factorial arrangement of genotype and acclimation (acclimation and non acclimation) were imposed as main plot and temperatures (0, -4, -8, -12, 16, -20ºC) as subplot. The effect of freezing temperature (FT) on plant survival was significantly different among genotypes (p<0.05). According to the average effects of acclimation and FT, the plant survival in MCC426 and MCC252 was 40% and 31% respectively more than in MCC505. Lethal temperature for 50% response (LT50) and temperature resulting in 50% lower dry matter (DMT50) in MCC426 were –10.8ºC and –8.4ºC, respectively and were lower than the other genotypes. Acclimation increased the freezing tolerance such that MCC426 tolerated up to –12ºC without any mortality, however, at this temperature, plant mortality rates in MCC252 and MCC505 were 25.7% and 67.7%, respectively. Plant regrowth was affected by the intensity of FT, such that plant dry weight (PDW) and stem height (SH) in –12ºC decreased about 63% and 50%, respectively, compared with non - frozen control plants. The most freezing damage was observed in MCC505, -12ºC treatment caused 90% decreases in PDW and SH, but at this temperature, PDW and SH in MCC425 decreased 55% and 49% and in MCC252, the reduction was about 60%and 54%, respectively. It seems that the use of controlled experiments would contribute to the evaluation of freezing tolerance and screening programs in chickpea germplasm for the estimation of LT50 and DMT50 .

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The aim of this study was to use Alpha-amylase termamyl 2-x for maltodextrin production from corn starch and evaluate its industrial uses. Based on the results obtained in laboratory, this process was accomplished in pilot plant scale. The process included preparation of starch suspension, pH adjustment, addition of enzyme, heating under stirring, continuous control of DE and Brix, enzyme inactivation in adequate DE, separation of soluble sections by centrifuge and finally spray-drying of the maltodextrin liquid. In this investigation, the amount of DE at dry matter was calculated under three enzyme concentrations (0.2, 0.25 and 0.3 ml of Alpha-amylase termamyl 2-x per Kg of starch) and in three different hydrolysis temperatures (60, 65 and 70 ºC) at constant pH (6). A completely randomized design with factorial arrangement and 5 replications was conducted. To study the relationship between DE and different parameters, multiple linear regression was used. Finally, for approximation of DE (based on enzyme concentrations, temperatures and hydrolysis times) a regression model was used. The results from different enzyme dosages at the same temperature and time of hydrolysis differed significantly (p≤ 0.05). Meanwhile, the best enzyme concentration and hydrolysis temperature for maltodextrin (high DE) production after 300 minutes were 0.25 ml of enzyme per kg of starch and 70 ºC, respectively. In these conditions, the least residual starch concentration and residual Alpha-amylase activity were observed.

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Cantaloupe (Cucumis melo L.) is one of the most important melons in Iran especially in Khorasan province. The cantaloupe seed is a good functional and nutritional source for human, having large amounts of essential amino acids and unsaturated fatty acids. In spite of nutritional and functional aspects, it does not have considerable applications in food industry yet. Cantaloupe seed milk's pH is about 6.8, so cannot be stored for a long time. In this work, pH of cantaloupe seed milk decreases to 4.15 in 3 treatments (citric acid, orange concentrate, and orange sacs) and a constant amount of lemon juice. At first, nutritive value of seed milk was measured. According to results, this milk is a good source of protein (1.52%), phosphorus (41/3 ppm) and potassium (17 ppm). After that, storage stability of cantaloupe seed beverage at refrigerator temperature (4 °C) for 42 days was evaluated by analyzing changes in the chemical, microbial and sensory properties. The results showed that the orange concentrate-cantaloupe seed beverage reached the highest score of total acceptance (3.67 on a 5-point hedonic scale). In these conditions, we couldn’t find any molds and yeasts in the samples, thus the shelf life of the mentioned beverage could be 6 weeks at 4 °C.