فصلنامه پژوهش و نوآوری در علوم و صنایع غذایی
سال ششم شماره 1 (بهار 1396)

In this study, the effect of sesame oil mixture (1 and 2% w/w concentrations) and unsaponifiable components (0.02 and 0.04% w/w concentrations) was compared with frying oil in terms of acrylamide content, oil absorption and moisture in donuts during deep frying process at 180oC. The data were analyzed in completely randomized design based on Turkey test. The results showed that considering the antioxidant role of sesame oil and its water barrier effect, the level of acrylamide and oil absorption were lower in all samples compared to control sample. Performance of fried samples containing 0.04% unsaponifiable compounds of sesame oil was much better than other fried samples. Samples lacking sesame oil had the least effect on acrylamide content and oil absorption compared with other samples. Samples fried in 2% sesame oil had 9.6 measure oil absorption and 45.20% acrylamide reduction compared with control sample. In addition, in samples fried in oil containing 0.04% unsaponifiable compounds, oil absorption, acrylamide content and moisture decreased 8.9 units, 58.64% and 13.33 units compared with the control sample, respectively.

Assessment of quality characteristics of agricultural and food products has been associated with many problems. The main purpose of this study was the evaluation of morphological characteristics of raw cane sugar crystals and then estimation of the raw cane sugars quality using digital image processing techniques. The quality properties of raw cane sugars such as ash content, sucrose content, invert sugar, color solution, pH, concentration of starch and dextran, moisture content and refractive index and also different morphological characteristics such as area means and medians of crystals, perimeter means and medians of crystals, quadrangle ness means and medians of crystals and count number of crystals were identified using digital image processing. The results demonstrated that there was a good correlation between morphological and some physicochemical properties of raw cane sugar such as ash, sucrose content, concentration of starch and dextran as well as refractive index using the obtained equations, some of the quality parameters can be estimated by their morphological characteristics.

Pistacia atlantica is the dominant species of Pistachio in Iran. Mastic Gum is a resinous gum, which is called Saghghez in Iran. Firstly, the essential oil (EO) of Pistacia atlantica gum was extracted by hydrodistillation method, then the starch film containing Pistacia atlantica essential oil at 0, 0.5, 1 and 2% (V/V) were prepared applying casting method and their physicochemical, mechanical, permeability properties were evaluated.The results showed that the incorporation of EO caused a significant increase (P

In this study, the effects of pulse elecrocoagulation (PEC) process on apple juice clarification was investigated. Influences of three variables of pulse time (1, 3 and 5 seconds), process time (5, 10, 30 and 45 minutes), and electrical current (0.03, 0.1 and 0.5 Ampere) on process efficiency were studied in three repeats. The results revealed that the minimal turbidity 5 NTU was achieved at 0.03 ampere of electrical current, 5 minutes of pulse time, process time 30 minutes, and natural juice pH (pH=3.5). In order to attaint apple juice turbidity standard level, the synergistic effect of low amounts of pectinase, amylase, and gelatine fining agents were used as co-coagulant. Using this method reached turbidity up to 3 NTU wich is very close to industrial standard turbidity (2 NTU) and this level is generaly required to produce stable clarified juice. This study showed that PEC can successfully be used as an alternative or an auxiliary method for juice clarification because of high turbididy removal potential in noticeable lower process time and lower amounts clarifying agents.

This study was performed in order to examine the effect of verjuice concentration on the physicochemical and textural properties of beef Biceps femoris, which aimed at improving its tenderness and enhancing its marketability. To that end, verjuice (0, 30, 70 and 100%) and sodium chloride (2% w/w) were injected into the beef pieces with dimensions of 3×15×15 cm3 (10% of each piece initial weight). Then, for the uniform distribution of the solution on the surface and deep parts of the beef, the samples were immersed in verjuice solution (with the same concentration as was injected and at a ratio of 4:1) and stored at 4 °C for 12 h. The results showed that as verjuice concentration increased, pH decreased significantly (P

Chitosan and gelatin are biopolymers with preservative effects and film forming ability to form antimicrobial and antioxidant coatings and films. In the current study, the effect of chitosan (1% w/v) and gelatin (3% w/v) coating (composite and bilayer) and film (composite and bilayer) was investigated on the storage of Johnius belangerii fillet in refrigerator (4 °C) for 16 days. Bacterial experiments (total count, pscychrotrophic bacteria and enterobacteriaceae) showed the antibacacterial effect of chitosan-gelatin coating and film but there was no significant difference between coating and film or composite and bilayer. Lipid oxidation value experiments (thiobarbituric acid and free fatty acid values) showed lower oxidation value in coated and film wrapped fillets. Also, sensory evaluations showed that refrigerated coated and film-wrapped samples had more durability (4 days) than control. Thus, chitosan-gelatin as edible coating and film (composite and bilayer) can enhance shelf life of Johnius belangerii fillet during refrigerated (4 ± 1 °C) storage.

Drying of agricultural and horticultural crops is one of the most important processes for their long term storage. Therefore, in this study, the influence of drying temperature and air flow velocity on the variation of color, shrinkage and pH were investigated during the drying process of thin-sliced Dargazi pear varieties. Drying air temperature varied in four levels of 50, 60, 70 and 80 °C and the air flow velocity at three levels of 0.5, 1 and 1.5 m/s. The image processing results indicated that maximum variation of the sample’ color (30.78) occurred at drying temperature of 80°C and air velocity of 1.5 m/s. In contrast, the minimum variation of the color (14.38) occurred at drying temperature of 50 °C and air velocity of 0.5 m/s. The results indicated that PH of the examined samples increases during the drying process. The maximum value of pH (4.49) was obtained at drying temperature of 50 °C and air velocity of 0.5 m/s, whereas the minimum value (3.93) was measured at 80 °C and air velocity of 1.5 m/s. Given the overall results obtained in this study, minimum drying time with minimum variation of qualitative specifications occurred at drying temperature of 70 °C and air flow velocity of 0.5 m/s; therefore, this condition could be suggested as the best combination for drying of thin-sliced pears.

In this research, the effect of tragacanth gum (Astragalus gummifer) at five different concentrations of 0.25, 0.5, 0.75 and 1 gram of gum per 1 kg of consumed milk on physicochemical (moisture, ash, pH, salt, fat and protein), colorimetric measurement and textural properties of Lighvan cheese during 90 days of ripening (0, 15, 30, 45, 60 and 90 days) was evaluated. The results showed that gum addition, decreased the fat content of Lighvan samples in comparison of control one. Gum increased the moisture and protein of samples in comparison with control. Fat, ash, salt and protein of Lighvan cheese increased during ripening. Textural properties (hardness, cohesiveness, gumminess, chewiness and springiness) significantly (P0.05) increased with addition of 0.25 gram of gum in one kilogram of primary milk before cheese-making; however, these parameters decreased at higher gum concentrations. All textural parameters of cheese decreased during 90 days of ripening. Colorimetric observation revealed that L* and b* parameters decreased and increased during ripening, respectively. Finally, based on textural properties of Lighvan cheese, X0.25 sample was selected as the best formula in five produced cheeses.