ELECTRONIC JOURNAL OF FOOD PROCESSING AND PRESERVATION
Year:2020 | Volume:12 | Issue:1|Papers Count:11

Background and objectives: Diabetes mellitus is a chronic disorder in carbohydrate, fat and protein metabolism characterized by increase in blood sugar in the patient. The long-term complications of this disease is cardiovascular, renal failure and neurological activity. The use of herbal medicines for the treatment of diabetes is increasing day by day and this has made it more important to recognize the effective herbal medicine. Herbal remedies have been taken into consideration because of fewer complications, reasonable prices, and availability of chemical drugs. The Momordica charantia (Linn Family: Cucurbaceae), whose fruit is known as Karela or bittergourd, is an important anti-diabetic plant. One of the anti-diabetic agents of Karela is Polypeptid-P (p-insulin), a 172 amino acid. The content of polypeptide-P in cultivated plants is relatively low so gene cloning and expression of this polypeptide in microorganism is a quick and useful alternative for solving such problem. The probiotic host has the advantage that after the production of target protein, it is not necessary to purify it but producing recombinant protein in other expression hosts need to be purified. Therefore, in this study p-insulin gene was optimized and expressed in probiotic yeast Saccharomyces boulardii. Materials and methods: In this research, the sequence of p-insulin gene was optimized for both codon bias and secondary structure of mRNA to effectively express in the probiotic yeast Saccharomyces boulardii. The optimized gene was cloned into the pESC expression vector under Gal10 promoter and transformed to competent cell. Recombinant yeast was extracted DNA then the PCR reaction was done by p-insulin specific primers. Recombinant yeast was induced by galactose and production of P-insulin protein in the recombinant yeast cytoplasm was verified by SDS-PAGE and mass spectrometry. Results: A 350 base pair production was amplified by p-insulin specific primers in the polymerase chain reaction. SDS-PAGE electrophoresis pattern was compared host S. boulardii and transformed S. boulardii carrying pESC/p-insulin construct. Electrophoresis results showed that the 18. 5 KD molecular weight p-insulin protein differential band was expressed just in the recombinant yeast and also mass spectrometry results confirmed differential band as a p-insulin protein. Conclusion: In this study, probiotic yeast Saccharomyces boulardii was used as a successful host to producing p-insulin protein for the first time. This research showed that probiotic yeast S. boulardii can used as a suitable host cell to producing other products in the food and pharmaceutical industries.

Background and objectives: Hydrolysis protein is obtained by breaking the protein into peptides by enzymatic or chemical reactions. In conditions of freezing, compounds with low molecular weight have fatty oxidation and protein degradation, which is associated with bad odor and taste, and affects the qualitative characteristics of the tissue, so if it can be added by adding hydrolysis protein, surimi result will be better at refrigeration and fresh temperatures. This study aimed to investigate the effect of hydrolysis shrimp on chemical, microbial and tissue changes of surimi silver carp (Hypophthalmichthys molitrix). Materials and methods: Silver carp was converted to bone-free meat by a bone-like machine with a diameter of 2 mm. The non-bulging meat was then washed three times with cold water. The volume of water consumed was 4 times the weight of the meat at each time (ratio 4: 1). In the third step, 0. 2% sodium chloride was added. In the final dewatering stage, after pressing the meat on the hand of the fish, a heavy weighing pad was placed on the meat grinder for 10 to 15 minutes to completely remove the water. To prepare hydrolysis shrimp, 250 grams of honeydew taken from Hanijan, peeled and boiled, were hydrolyzed by the alkaline enzyme. Hydrolyzed shrimp was added to surimi at 0. 5, 1 and 2% control levels. To carry out this research, for 15 days, refrigerated temperature was measured by measuring microbial load (TVC), biochemical parameters, and texture and color measurements. Results: The results showed that the hydrolysis protein had inhibitory effects on microbial growth, and in none days, the amount of microbial load did not exceed the permitted limit (107 Log cfu / g) and the microbial load on day zero compared with day 15, in Treatments were significantly increased, but this increase was lower in hydrolyzed protein treatments, especially at 2% level compared to lower levels and control. pH increasing trend during all treatments. Frequency of free fatty acids (FFA) showed a significant difference between different treatments (P <0. 05). The highest value of this parameter was observed with respect to day zero to day 15 and in control treatment (4. 25 ± 0. 03%). In all treatments, peroxide levels did not exceed the permitted level (20-10 mg / kg). In control treatments, and 0. 5% of volatile fatty acids increased from (0. 4 ± 0. 004) to (4. 25 ± 0. 03%) at the end of the period, while in other treatments this increase was slower. The lowest TBA was measured in 2% treatment. The highest value of this parameter was measured from day zero to day 15 and in control treatment (4. 44 ± 0. 54 mg malondialdehyde in kilograms). The amount of volatile nitrogen (TVN) showed a significant difference between treatments (P <0. 05). The lowest value of this parameter was zero in day 0 and the highest value of this parameter was significant with respect to day zero, to day 15 and control (63. 85 ± 1. 5 mg/ 100 g sample). Protein hydrolysis also affected surimi's tissue properties. In the results of the color analysis, the brightness parameters (L) and redness (b) decreased and the jaundice parameter (a) increased. Conclusion: Based on the results, 2% treatment of hydrolysis shrimp could retain surimi's silver carp for up to 12 days.

Background and objectives: Starch is the most widely used natural polysaccharide in the food industry, which plays a significant role in the consistency, texture and nutritional value of food products. Although natural starch from various plant sources has unique properties, with the advancement of food technology and the development of new methods of food processing, the structure of starch changes which can lead to the loss of some of its desirable properties in foods. In order to improve the functional properties of starch, its structure can be modified through modification. The aim of this study was to evaluate the effect of acetylation and cross-linking on functional properties of acorn starch in comparison to commercial wheat starch. Materials and methods: In this research, the acorn fruit was collected from mature trees located in Baghmalek in Khuzestan province, and its starch was extracted. To compare with a high-consumption starch, commercial wheat starch was used as a reference. The chemical composition of wheat and acorn starches was measured using standard AACC methods, amylose was measured based on the formation of a blue complex with iodine reagents and reading of absorbance at 615 nm. Modification of starches by cross-linking methods at 0. 1%, and percentage of acetylation and degree of substitution with 6% acetic anhydride was measured accurately using the titration method, and the swelling factor was determined. Syneresis was measured during days 1, 2, 3, 4, 7. Statistical analysis was performed using SPSS software and comparisons of the meanings by Duncan test at 5% probability level. Results: The results showed a significant difference in the amount of amylose in natural starch of wheat and acorn. Fat, moisture and protein content of two starches showed a significant difference but there was no difference in ash. The protein and moisture content of acorn starch was higher and its fat was less than wheat starch. The percentage of acetylation and degree of substitution were significantly different in two studied starch. Cross-linking reduces the factor of swelling and acetylation caused increased swelling factor in the two examined starches. The highest swelling factor was indicated in acetylated wheat starch and the lowest swelling factor was indicated in cross-linking acorn starch. Syneresis was the highest in cross-linked wheat starch and the lowest in acetylated wheat starch. Conclusion: The results of this study showed cross-linking could be caused to decrease and increase the swelling factor and syneresis in modified starches compared to natural starches in both studied starch respectively. On the other hand, acetylation of starch caused decreasing and increasing the syneresis and swelling factor in modified starch respectively compared to natural starches of wheat and acorn. Therefore, the degree of cross-linking is an important factor in creating the desired properties. The Cross-linked starch of acorn in food products can be used to improve the crispness of crispy crackers and biscuits, as well as acetylated starch could be used as the thickening agent in soups, sauces, stews, bakery products, dairy products, and baby food. Also, due to the low amylose content of acorn starch and suitable functional properties it is suggested that application of acorn starch as an alternative starch in food industry evaluated in future studies.

Background and objectives: Tomato based products have high nutritional value, amazing color, desirable flavor and high stability. Application of an appropriate processing method is needed to preserve the quality of these kinds of products. Todays, to produce the high-quality food products, novel thermal and non-thermal treatments are applied. In this study, a continuous pulsed electric field (PEF) system equipped with infrared irradiation (IR) was designed and constructed. Effect of this novel tomato juice processing method on ascorbic acid (AA) content was investigated. Some mathematical and kinetic models were also used to describe the AA degradation. Materials and methods: The square-bipolar wave with 1 ms width at a constant frequency (32 Hz) was applied during PEF treatment. Two stainless steel electrodes, 10 mm in length and 0. 5 mm in width were used in the PEF chamber. At first, tomato juice (30℃ ) was preheated up to 40, 45 and 50℃ ; the sample was then PEF processed at 22. 73, 27. 27, 31. 82 and 36. 36 kV/cm for 1173 to 3520 􀟤 s. AA content was measured using the iodine titration method. Results: IR-preheating up to 40, 45 and 50℃ resulted in 11. 41%, 16. 39% and 19. 01% decrease in AA content. Higher vitamin degradation was observed when higher PEF strength and longer processing time. Models such as first-order semi-logarithmic, simplified Hulsheger, Fermi and Hulsheger were applied to study the effect of process conditions on AA degradation. Conclusion: AA content significantly reduced during IR pre-heating. First-order semilogarithmic model was useful in studying the effect of PEF treatment time on AA degradation. Considering the high correlation coefficient and low standard error, simplified Hulsheger was selected as the best one in describing the reduction in this vitamin content in relation to changes in PEF strength. Hulsheger model was also effective in predicting the vitamin degradation at different PEF strength and process time. It can be concluded that the applied PEF strength and processing timed should be controlled to prevent from more heating up the juice by considering the ohmic heating effect.

Background and objectives: Toast bread belongs to the bulk breads group that is recently bulk considered to be the most popular bread in Iran. The quality of breads depends on the baking power of the flour, the time of fermentation, the amount of protein and the type of additives which had been added. In addition, the outcome of the baking flour can be compared by the characteristics of the flour, the type of industrial measures, the method of preparation and the dough preparation process. By considering the bread position in the diet of individuals, it is possible to increase the nutritional value of this product by using different functional compounds of which fibers are widely considered. There are several reports indicating the daily intake of fiber is lower than the recommended dose that may increase the incidence of various diseases such as obesity and diabetes. During the recent years, however, efforts have been made to increase the use of dietary fiber in various food sources due to its impact on health. Therefore, in the present study, the effect of adding different levels of Oat and Psyllium fibers as new sources of dietary fiber on the quality of toast bread was investigated in comparison with the control sample. Materials and Methods: Firstly, chemical properties of the used wheat flour was determined. Then the raw materials had been prepared according to the treatments for preparing the dough. The treatments consisted of regular toast as the control, toast bread containing 0. 5% (of flour weight) oat and psyllium fiber, toast bread containing 1 % of oat and psyllium fiber, toast bread containing 1. 5 % of oat and psyllium fiber and toast bread containing 2% of oat and psyllium fiber which were subjected to various evaluations including the amounts of moisture, ash, protein, fat and fiber, pH values, as well as volumetric, texture analysis, colorimetric and sensory characteristics. To analyze the data, a completely randomized design was performed. The comparison of mean values was done by Duncan's multiple range test at a probability level of α = 5% Results: According to the results, with increasing the levels of Oat and Psyillium fibers, the values for moisture, ash, fiber, bread volume and L* were increased but pH, protein, fat, a* and b*, and staling rate decreased compared to the control. Application of fiber compounds also improved most sensory characteristics such as porosity, texture, chewing ability, taste, color intensity of crust and crumb and also aroma. Conclusion: The treatment containing 2% of oat and psyllium fibers were found to be the best treatment in this study. According to the results, it seems that oat and psyllium fibers can be used to improve the qualitative and organoleptic characteristics of the toast bread.

Background and objective: The synthetic antioxidants, which have many side effects on human health, are commonly used to control the oxidative stability of oils. So today, researches on essential oil of herbal plant as a safe alternative method are in progress. The aim of this study was application of essential oil of peppermint (PMEOs) medicinal plant (as a natural antioxidant) to improve the oxidative stability of soybean oil. Materials and methods: In this study, the quality properties of soybean oil were evaluated after the addition of natural antioxidant of peppermint essential oil (Mentha piperita) with peroxide index, induction period, acidic number, thyobarbituric acid index and oxidative stability index during storage period (for 45 days). For this purpose, by using the response surface method (RSM), the optimum concentration of essential oil was determined with respect to the peroxide index and the induction period factors (by the accelerated shelf life test at 60oC). Then, PMEOs antioxidant was added to soybean oil at optimum concentration and the noted quality properties were compared during the storage period with the blank sample. Also, obtained results from this study were repeated with a sample of soybean oil containing BHT synthetic antioxidant. Moreover, in this research, the factorial experiment in a completely randomizes design was used to analyse the data of the storage stage. Mean comparison of data was carried out by least significant difference test (LSD) in confidence level of 99%. Results: Gas chromatography-mass spectroscopy (GC-MS) test was used to confirm of the PMEOs. Based on the results, totally 37 components were identified in essential oil of this herbal plant. The main components of the essential oil of this herb plant include iso-Menthol (34. 58%), Menthol (29. 81%), 1, 8-Cineole (5. 93%), Menthofuran (4. 49%), iso-Menthone (3. 51%), Menthol (3. 4%), cis-Sabinene hydrate (2. 31%) and D-Limonene (1. 81%). The results of this research indicated that variation trend of peroxide index, acidic number and tiobarbitoric acid index increased during storage from 1st to 45th day, whereas the induction period of soybean oil showed a decreasing trend. Also, the result of this research indicated that blended of PMEOs (or BHT) could be reduce peroxide index, acidic number and tiobarbitoric acid index than blank sample to 37. 57% (35. 49%), 54. 24% (48. 3%) and 15. 45% (2. 44%) during 45 day storage. Furthermore, the PMEOs (or BHT) than blank sample increased induction period to 13. 53% (37. 44%) during 45 day storage. Conclusion: Overally, the results of this study showed that PMEOs (with concentration of 871 ppm) as a natural antioxidant could be improve the quality properties of soybean oil.

Background and objectives: Proteins and polysaccharides are common compounds in many food formulations. They are responsible for some food characteristic, such as texture and controlled release of flavor. They can modify phase stability in colloidal food systems. These biopolymers play an important role in structuration and stabilization of food through their gelling, thickening and surface activity properties. The products of this reaction are new materials that have different functional properties in comparison with reactants. The aim of this study was to investigate the structural, functional and antioxidant properties of protein-free balangu seed (Lallemantia royleana) gum. Materials and methods: Balangu seeds were purchased from a local market in Bojnord. Protein-free Balangu was achieved by protease hydrolysis (by proteinase enzyme K). To inactivate the enzyme, ethanol added at ratio of 3 to 1 on the system and kept for 6 h. Then, polysaccharide was separated and resolubilized in water and the resultant solution was centrifuged at 15, 000 × g for 15 min and the supernatant was named as protein-free fraction. The samples were dried in an air forced oven at 38 ̊ C. To evaluate the functional properties of the gum, different parameters such as surface tension (using a Wilhelmy plate technique with a platinum-iridum plate), emulsifying properties (particle size distribution in emulsion, light microscopy, emulsion stability in storage period and emulsion stability test centrifuges) and foaming properties (foaming capacity and foaming stability). Moreover, the antioxidant activity balangu gum and protein-free balangu were measured by two methods, DPPH free radical scavenging and FRAP assay. Butylated Hydroxy Toluene (BHT) was used as positive control for comparison. A completely randomized design was used for statistical analysis. The data was statically analyzed by Analysis of Variance (ANOVA) and Duncan Multiple Range Test. The P level of <0. 05 was considered statistically significant. Results: The results showed that a decrease in protein content of balangu seed gum by protease enzyme led to significant reduction in surface activity and weakened emulsion and foam stabilization properties of balangu seed gum, which presents the importance of protein in emulsifying and foaming properties of balangu seed. Antioxidant activity of the gum and protein-free fraction in the both methods were less than standard BHT. Protein-free fraction had the lowest protein content which caused a sharp reduction in its antioxidant activity compared to the primary gum. Conclusion: The functional properties revealed that the balangu seed can be well used as an emulsifier and foam stabilizer.

Background and objectives: Peppermint is an aromatic herbal plant in which its essential oil possesses many polyphenolic compounds with anti-bacterial, anti-fungal, antioxidant and free radicals scavenging properties. Microencapsulation by spray drying is one of the most effective methods which has increasingly being used in recent years. This process is regarded as an important industrial operation for physical coating of liquid or semi-liquid foods with a thin layer of protective layer to preserve them against any chemical spoilage, to increase powder productivity, to facilitate dry blending of powdered food with other ingredients and finally, to increase the shelf life of dried food. The objective of this study was to investigate different concentrations of carrier substance, Arabic gum (AG) and different inlet air temperatures on production yield of powder and different physical properties of spray dried peppermint powder. Materials and methods: A co-current pilot scale spray drier with rotating atomizer was used. AG as a drying aid substance at concentrations of 10, 20 and 30% (w/w) was used. Inlet air with a temperature of 140, 160 and 180 ° C was used at a co-current stream with feed material. In all experiments, atomizer rotational speed, raw material feeding rate, feed temperature, and air nozzle pressure were 18000 rpm, 25 ml/min, 30± 1 ° C and 4. 2± 0. 1 bar, respectively. Moisture content, aw, production yield, solubility, hygroscopicity, wettability, and objective color parameters of spray dried powders were determined. Results and discussion: Results showed that increasing inlet air temperature and AG concentration (up to 20%) led to an increase in production yield. However, concentrations more than 20% decreased production yield. Hygroscopicity of powders was increased with temperature, and decreased with increasing in concentrations of AG. Moisture content, aw, wettability, solubility were decreased with increasing in air temperature and AG concentrations. The results of objective color measurement revealed that increasing in air temperature and AG concentration led to an increase in L*; However, a*, b*, chorma and hue indices were decreased. Conclusion: It was concluded that the inlet air temperature of 160 ° C and Arabic gum concentration of 30% were the optimal parameters in spray drying of peppermint yeast extract.

Introduction: Cactus prickly pear is a plant of the cactus (Opuntia stricta), some species of this plant used in this research grow in the regions of southern Iran and the coastal seas of Mazandaran. It is very important to peel in the process of producing products from prickly pear fruit. Optimum heating and infrared irradiation can be used as a suitable and effective method in the pretreatment process with the aim of reducing the consumption of chemicals and harming the environment and increasing the quality of the product. Methods: In this study, using the precursor of ohmic compared to the control sample, the effect of field intensity (1500 to 4500 V / m) and the concentration of sodium chloride (0. 01-0. 03 g / 100 milliliters) and the effect of three The variable power of the device (350 to 850 watts), the distance between sample and IR radiation source (10 to 30 millimeters), and the IR radiation time (45 to 125 seconds) were inflamed irradiation on weight loss, skin thickness, and total phenolic compounds, The amount of ascorbic acid and colorimetric indices L *, a * and b * were studied in Barbed Pear Fruit. Color determination with IM software, ascorbic acid content was determined by iodometric method, thickness with micrometer and phenolic compounds by Folin-Sioukalto method. Hand-peeled prickly pear was considered as a control sample. Results: With increasing field strength and increasing salt concentration of sodium chloride, more favorable results were obtained. The best ohmic treatment with a field strength of 4500 V / m and a concentration of sodium chloride 0. 03 g / 100 ml, the values obtained for weight loss 8. 2 ± 0. 57, ascorbic acid content of 1. 1 ± 0. 005 Milligrams per 100 milliliters and total phenolic compounds totaling 14. 52 ± 0. 8 mg gallic acid per 100 grams, and also the optimum conditions for baking pears with infrared irradiation is 652. 2 W, 45 seconds and 4 cm intervals. In these conditions, the values obtained for each response with the highest degree of utility (0. 754) were as follows: weight loss 12. 15%, total phenolic compounds totaling 13. 354 mg Gallic acid de 100 g, the content of ascorbic acid in 100 ml mg 0. 9823. Conclusion: Prickly pear peeled with ohmic and infrared heaters showed significantly higher ascorbic acid content in fruits than fruit juices, more phenolic compounds in the skin and less weight loss. Also, the best treatment for optimum infrared temperature was more suitable.

Background and objectives: Recently there has been a growing interest toward the utilization of sonication considering its high efficiency and accessibility. High power ultrasound waves make sinusoidal moves through the liquid environment and create unstable vacuum bubbles which are growing in size till disrupt. Their disruption lead to the creation of spots of very high velocity and temperature. The large particle and molecules located near this spots degrade and produce particles or molecules of smaller size. It is generally accepted that ultrasonic degradation of polymers in solution is of mechanical nature rather than thermal in origin, and that the stresses induced in polymer molecule are caused by the friction forces generated by the relative movement of the molecules of solvent and polymer as a result of the collapse of cavitation bubbles. In this research, the effect of different ultrasound power and temperature on the oat starch properties was investigated. Materials and methods: Extracted oat starch with determined chemical composition was sonicated by using a 20 kHz ultrasound probe at 150 and 350 W power at 25 and 50 ̊ C for 10 min. Sonicated oat starches were recovered by centrifugation and drying. Afterward, the various chemical and physical properties of native and sonicated oat starch such as solubility, swelling power, thermal properties, textural properties, water and oil absorption capacity and retrogradation were investigated. under different combination of heat and sonication power were investigated. Results: Ultrasound treatment had significant effect on oat starch properties. The results indicated that increasing the power and temperature, enhance the effect of ultrasound on different oat starch properties. Swelling power, solubility, gel clarity, and gelatinization temperature parameters were significantly increased due to the higher power and temperature of sonication. Retrogradation of sonicated starch samples was significantly lowered as compared to naï ve oat starch samples. Gels prepared from sonicated oat starch had significantly softer texture compared to the native oat starch gels. These changes could be mainly due to disruption of amorphous and weaker crystalline structures and also the degradation of high molecular weight molecules to molecules of smaller size. Swelling power, solubility, gel clarity and gelatinization temperature were increased while the reverse trend was observed for gel hardness and retrogradation. This changes could be mainly due to the destruction of amorphous and weak crystalline structure of starch granules. Conclusion: These results declared that oat starch properties would be affected by ultrasound treatment, And as compared to the control, it’ s revealed that the effect of higher power and higher temperature were more pronounce that lower temperature and lower powers. Finally, regarding the proper characteristics of starches modified under the sonication condition of 350 W power at 50 ̊ C (e. g. soft and stable structure of gel with low tendency toward retrogradation and opacity), this treatment is recommended as the optimum condition.

Background and objectives: Rice is the predominant staple food in tropical and semitropical areas. Carbohydrate is the main component of rice that accumulates in endosperm. Postharvest treatment and storage duration (as the aging process) is a complicated process, which results in changes in physical and chemical properties of the rice grain especially of aromatic rice varieties. In this study, the effect of polishing process and storage duration on the stability of aroma components in rice (Tarom variety) was investigated. Materials and methods: Rice (Tarom variety) was dried and then dehusked by hand. The weight of brown rice was measured manually and it was polished by multi-stage polisher. The brown rice and white rice samples were divided in two groups; non-stored and stored brown rice (NBR, SBR) also non-stored and stored white rice (NWR, SWR). The volatile components of NBR, SBR, NWR and SWR samples were absorbed by solid phase micro extraction method and measured by gas chromatography (GC). Analysis of variance was performed as factorial experiments in a completely randomized design. The two factors were polishing type and storage, with two levels and three replications. The values were analyzed by using SPSS software. Results: The results showed that the percentage of identified components of all stored rice samples increased significantly (P<0. 01), while the aromatic components percentage of new white rice samples (WSN) were increased in compare of stored white rice samples (WSO). The results of the present study on the effect of storage duration on the aromatic components exhibited that by removing of bran layer in whitening process result in reduction of aromatic components. The recognized components in samples are as follows; 24 component for BSO (about 92. 3% of total), 26 component for WSN (about 65. 3% of total), and 24 component for WSO (about 98. 4% of total). Storing and whitening could increase the amount of Alkenes in rice volatile component. The higher rate of 2-Methyl-octadecadienol as an alcohol might be due to using of insecticide in paddy fields which was reduced after whitening process. The percentage of Aldehyds & Ketons has no meaningful difference in brown rice stored samples but it was decreased about 30% in white stored rice samples. Conclusion: From the results of this work, aging the aromatic variety not only increases the cost of keeping but also could reduce the aromatic component as a rice quality index.