FOOD ENGINEERING RESEARCH (JOURNAL OF AGRICULTURAL ENGINEERING RESEARCH)
Year:2019 | Volume:18 | Issue:66 |Papers Count:12

The aim of this study was to find an optimal condition to produce lactic cheese using three independent variables: amount of microorganisms as starter, baking temperature of curds, and pH of curd during cutting. Results indicated that the linear term of pH had the greatest effects on the cheese efficiency and calcium content, and the square term of the baking temperature had the greatest effect on the texture and the overall acceptance of lactic cheese. The square term of baking temperature of curd had the greatest effect on ACE inhibitory and antioxidant activities, and the color and flavor properties of lactic cheese. The starter used in lactic cheese improved the functional, physical and sensory characteristics of the cheese. It has been found that the performance of the response surface methodology in optimizing the lactic cheese formulation was reasonable. The treatment containing 1. 75% starter with curd baking temperature of 42 ° C and curd cutting pH equal to 4. 7 has been found as the optimum treatment for lactic cheese. In this situation, we came to the following conclusions: the level of cheese production efficiency = 19. 48%; ACE inhibitory activity= 0. 16 m/ml; antioxidant activity = 36. 15%; calcium content = 0. 42%; texture acceptance = 3. 9, color acceptance =4; , taste acceptance =4. 2; and total acceptance =3. 9.

In this study, the effects of different levels of chicken feet gelatin (3, 5 and 7%) and different levels of grape concentrates (60, 70 and 80%), as a natural sweetener, on the color parameters of ginger gummy confection were evaluated, using response surface methodology and sensory test results, as well as the principal component analysis. The microbial test of gummy confection samples was performed according to standards. Decrease in L* (transparency) of the gummy confection and increase in a* (redness) and b* (yellowness) levels occurred when the levels of gelatin increased, but an increase in grape concentrates had a direct positive effect on the redness parameters of the samples (p<0. 01). Levels of gelatin and grape concentrates, 3. 01 and 60% respectively, have been found the best formulation for the gummy confection. In the microbial tests, growths were observed in lactic acid bacteria, acid-resistant bacteria and antibiotic resistance bacteria in GC1 (3% gelatin and 60% grape concentrate), GC4 (5% gelatin and 60% grape concentrate) and GC7 (7% gelatin and 60% grape concentrate), and no growth was observed in the other samples. No growth of mold and yeast occurred in any of the samples. However, in non-ginger (control) samples, the highest microbial growth (above the limit) was observed, indicating a strong antimicrobial effect of ginger. Sensory test results showed that GC6 (5% gelatin and 80% grape concentrate) had the highest overall acceptance. Principal component analysis method also showed that the overall acceptance of the samples is related to the color, taste and stickiness of samples. It is possible to achieve a high overall acceptance by improving the color, tasting and reducing the stickiness of the ginger gummy confection.

This study was conducted to find out the concentration of lead (Pb), mercury (Hg), cadmium (Cd), arsenic (As) and chromium (Cr) in different parts of Salicornia persica Akhani plants (roots, stems, leaves and seeds), grown in the Rud Shur Mardadabad, and to compare the pattern of accumulation of these heavy metals, and to understand the translocation and bio concentration factors of heavy metals in different parts of the plants. The patterns of accumulation of metals were Cr>Pb>Hg>Cd>As for roots, Cr>Pb>Cd>As>Hg for stems, Pb>Cr>As>Cd>Hg for leaves and Pb>As>Cr>Cd>Hg for seeds. The concentrations of all heavy metals studied in different parts of this plant were significantly less than these of water and soil profiles (0-30 & 30-60 cm. depth). It was considered that the concentration of the elements in above ground parts of plants, even at their high concentrations in the soil, were kept at low levels. The bioconcentration index of all heavy metals in various parts of Salicornia plants ranged from 0. 1 to 0. 29. It was found that this species of Salicornia had no significant accumulation capacity for heavy metals and did not appear to be a suitable species for phytoremediation. The Salicornia plant with a translocation index of 1. 02 ± 0. 287 showed a high ability to transfer lead from the root to above ground parts. The lowest translocation factor was related to mercury metal (0. 38 ± 0. 040).

Sprouting is responsible for about 12 to 15 percent of the potato waste storage. Despite of effective existing methods, such as the use of chloropropham to control potatoes sprouting, the emergence of harmful aspects due to application of this chemical preservative, and growing interests of consumers towards healthy foods, persuade us to use natural compounds to inhibit potato sprouting. In response to this need, Eucalyptus and Lavender extracts with different levels of concentrations, 0, 0. 5, 1, 2, and 4 g / L, were used each month to control sprouting (germination) of storage potatoes, Agria germin, for 6 months. A group of tubers were only treated by 37g chlorpropham (5 purity). Data were analyzed by completely randomized design with 3 replications and factorial experiment at 5% statistical level. Results showed that with increasing the concentration of extracts from 0. 5 g/l to 2 g/l, potato sprouting was controlled more effectively and significantly. Further increase in concentration of extracts did not have any effect. Usage of these extracts at concentration of 0. 5 g/l stimulated the tuber sprouting compared to the control. Using a concentration of 2 g / l of Eucalyptus and Lavender extract, germination of the tubers decreased 64 and 82 percent respectively, and also total weight of the sprouts declined 79 and 86 percent, respectively. The best effect was achieved by 2 g/l combination extract of Eucalyptus and Lavender which showed more than 90 percent reduction in tubers sprouting. Organoleptic evaluation of the boiled and fried potatoes, treated with chlorpropham (CIPC) or the combined extract of Eucalyptus and lavender, did not showed significant differences, but both of them, received more points compared to the control tubers.

Brown rice is important because of containing nutrients and biological active compounds. Texture of brown rice is one of the important factors in terms of acceptance by consumers. An investigation was conducted to compare brown rice and three different types of Hashemi rice, No. 1, No. 2, and white rice with different degrees of whiteness, 35. 1-35. 9, 39. 6-40. 1, and 54. 2-55. 5 respectively, to compare their properties: quality, amount of minerals, pasting properties and acceptance. Completely Randomized Design was used. The results showed that the effects of the whiteness on quality of cooked rice including amylose percentage, water absorption, time required for cooking, solid losses and pasting properties were significant )α =0. 05). Time required for cooking decreased with increasing in whiteness. Furthermore, all pasting properties increased with increasing the milling degree. Although brown rice was cooked after soaking in water for a longtime (18 h), it possessed highest stiffness of texture, mass roughness and particles when compared to other three type of rice. Brown rice had the lowest acceptancy, compare to other three samples. Rice 1 and 2 rated between white rice and brown rice in terms of quality characteristics, content of minerals and overall acceptance.

Melon seeds are nutritious grains that can prevent cardiovascular diseases and cancer due to its high levels of protein, omega-3 fatty acids, minerals, and dietary fiber. In this study, melon seed flour was added to the bread formulation at six levels of 0, 5, 10, 15, 20 and 25%. The results of physicochemical evaluation showed that the amount of protein, ash, bread fats, bread fibers and b* component significantly increased with increasing the amount of melon seed flour, while the moisture content of bread and color component L* decreased significantly compared to the control. From the point of specific volume and porosity of breads containing melon seed flour, the results showed no difference between control and the sample containing 10% of melon flour, but a significant decrease in those properties was noticed in samples containing 15, 20 and 25% melon seed flour, compared to the control sample. In texture evaluation of the samples, the results showed similarity between breads containing 10% and 15% of melon seed flour with control sample; the samples containing 5% of melon seed flour had harder texture than that of control sample and the samples containing 20% and 25% of melon seed flour possessed softer texture than that of control sample. In terms of general acceptance, breads containing 10 and 15 percent of melon seed flour were similar to the control sample. Therefore, adding 10% of the melon seed flour to the bread can improve the nutritional value of the bread while preserving the quantitative and qualitative properties of bread.

Nowadays, people's willingness to consume healthy and high-quality food products has led food producers to use natural ingredients with good functional properties in food formulations. Mulberry syrup has lower sucrose content in comparison with sugar and contains potent phenolic and antioxidant compounds. In this research, and in producing chocolate milk, mulberry syrup replaced with sugar at the same concentration (9%); tragacanth and basil gums (0. 3% and 0. 5% respectively )each one alone and in combination (0. 4% of each) were used as a replacement with commercial hydrocolloids. Physicochemical characteristics, phenolic compounds, free radical concentration (IC50) and sensory evaluations were investigated on the first day of production of chocolate milk. The results indicated that by replacing mulberry syrup with sugar and using tragacanth and basil gums in chocolate milk formulation, the amounts of sucrose, IC50, sediment and L* levels decreased (p≤ 0. 05) and the phenolic compounds, viscosity, a* and b* increased significantly (p≤ 0. 05). The results of the sensory evaluation indicated that tragacanth and basil gums in concentrations of 0. 3 and 0. 5% respectively did not affect all sensory characteristics of the treatments as compared to the control treatment. In comparison to control treatment, low-fat chocolate milk treatment, containing mulberry syrup and 0. 5% of basil gum, showed the highest amount of phenolic compounds and the lowest rate of IC50, lower sugar content and sediment, and proper qualitative properties (odor, taste, color, texture and overall acceptance); so, this treatment was consider as superior treatment in terms of health, qualitative and desirable properties.

Poor rehydration properties of skim milk powder (SMP) can impact processing efficiency and functionality in final product formulations. In this study, the effects of adding lecithin (1%) and tween 80 (0. 1%) as emulsifiers, di sodium EDTA and sodium citrate dihydrat (SCD) each one 5 mM as chelating agents, NaCl (0. 08%) and CaCl2 (0. 01%) as salts in improving rehydration characteristics of the product were investigated. These compounds were added to skim milk prior to spray drying and the effects of them on rehydration properties (wettability, dispersibility and solubility), microstructure and chemical properties of SMP were determined. Tween 80, EDTA and CaCl2 had a greater effect on improvement of the rehydration properties compared to other compounds. Tween 80 and CaCl2 also led to higher uniformity in the microstructure of SMP. Overall, the findings suggest that application of tween 80 combined with EDTA and CaCl2 might be an effective technique for improving SMP rehydration properties during reconstitution process.

Black hawthorn fruit (Crataegus elbursensis) is a source of natural antioxidants, especially flavonoids and anthocyanins, which have health effects, especially in the prevention of cardiovascular disease. This study was conducted to determine the effect of temperature and time of ultrasonic-assisted extraction process on extraction efficiency, free radical-scavenging activity and total phenolic and anthocyanin contents of hawthorn fruit. Ultrasonic-assisted extraction process was done at different temperatures (45, 55 and 65 ° C) and times (10, 20 and 30 min) and constant sample-to-solvent ratio (1 to 8) and ultrasound frequency (35 KHz). Total phenolic and anthocyanin contents were measured spectrophotometrically and the antioxidant activity of extract was assessed by measuring DPPH radical-scavenging activity (EC50) and Fe3+ reducing power. Statistical data analysis showed that at optimal conditions (extraction time 28. 85 min and extraction temperature (64. 86° C), extraction efficiency, total phenolic and anthocyanin contents, free radical-scavenging activity and Fe3+reducing power were 14. 31%, 1. 38 mg/ml, 7. 41 mg/ml, 0. 102 mg/ml and 248. 79 μ mol/l, respectively. Due to the high amount of bioactive compounds in the black hawthorn extract, the extract of this fruit can be considered as a natural additive and an agent for use in food.

In this study, inhibitory effects of herbal products (licorice root and neem leaf extracts, Aloe vera gel) on Aspergillus niger growth isolated from Mazafati palm dates and control of this mold in Mazafati palm dates were studied. The mold was isolated from rotten Mazafati palm dates. Herbal products were added to melted potato dextrose agar medium in different concentrations (0. 1, 0. 5 and 1% for Licorice root and neem leaf extracts and 0. 25, 0. 35 and 0. 50% for Aloe vera gel). Plates containing the herbal products were inoculated with fungi discs (7mm diameter) and incubated at 25° C ± 1. The diameter of fungus colonies (mm) were measured daily. There was significant difference (P < 0. 01) among the herbal extracts and also their concentrations in preventing Aspergillus niger growth. The results showed that inhibitory effects of licorice root extract on Aspergillus niger growth were significantly more than that of neem extract and Aloe vera gel. High concentration of the extracts had also more inhibitory effects on the mold growth. The licorice root extract at 1% concentration showed more reduction in the growth of Aspergillus niger and also was effective on control of rot in Mazafati palm dates. The licorice root extract did not make any special taste in Mazafati palm dates and obtained the more score in the sensory attributes (taste, appearance, acceptability).

In this study, the effects of combined osmosis and ultrasonic pre-treatment on the infusion of phenolic compounds extracted from grape residue into Aloe vera gel was evaluated, and the qualitative characteristics of dried Aloe vera samples were evaluated with hot air flow. For this purpose, the Aloe vera gel was prepared with agar and cut in the cylinder form (20 x 20 mm). The effects of different methods (osmotic dehydration, ultrasound prior and ultrasound assisted osmotic dehydration) on water loss, adsorption of solids, dehydration index and weight loss were measured. The samples were dried with a cabinet-dryer with a constant temperature of 60 ° C and air speed of 1. 5 m / s. The results showed that ultrasonic application had a significant effect on the physico-chemical properties of Aloe vera gel. The ultrasound assisted osmotic dehydration increased the amount of water loss and solids gain, comparing with other methods. The dried Aloe vera gel pre-treated with ultrasound assisted osmotic dehydration, had higher anthocyanin compounds and its color was lighter and reddened. The results of the sensory evaluation of the samples showed that this pretreatment improved the color, texture and appearance of the product

In this study, the effects of temperature, maltodextrin concentration and atomizer pressure on moisture content, yield (on dry weight basis), water activity, solubility, angle of repose and total anthocyanin (TAC) of Hibiscus sabdariffa L. and St' John's wort (Hypericum perforatum L. ) blend extract powder on quality and quantity properties of the powder were investigated. In this process, Maltodextrin was used as carrier agent. Experimental design involved the use of optimal design and response surface statistical method. Independent variables were inlet air temperature (120, 180 and 240 degrees celsius), concentration of drying aids (25, 35 and 45 percent) and atomizer pressure (0. 5, 1, 1. 5 kilograms per square centimeter). Optimization of production of Hibiscus sabdariffa L.-Hypericum perforatum L. blend extract powder with the aim of minimizing the amount of moisture content and water activity and maximizing the yield, solubility and total anthocyanin (TAC) were carried out using response surface methodology (RSM). RSM described that upon optimum conditions of 219 (degrees Celsius) inlet temperature, 42 (percent) maltodextrin concentration and 0. 5 (kilograms per square centimeter) atomizer pressure, it was possible to produce powder with yield (on dry weight basis) of 52. 68 (percent), moisture content of 1. 38 (percent), water activity of 0. 12, solubility of 95. 92 (percent), angle of repose of 20 (degrees) and total anthocyanin (TAC) of 52. 22 (milligrams per liter). Then, due to the importance of hypericin, the presence and stability of this material in produced powder in optimum conditions was confirmed by IR spectrometry analysis (FTIR).