مجله علوم و صنایع غذایی ایران
سال بیستم شماره 6 (پیاپی 139، شهریور 1402)

Because fat content has a great impact on the sensory properties of the cheese like appearance, taste and texture, its reduction causes fundamental changes in the sensory and structural characteristics of the product. Therefore, by using fat replacers, as well as to produce a healthy cheese, a product with an acceptable quality could be produced. In the present study, low-fat cheese samples (8% fat) were produced thru ultra-filtration (UF) method. To produce the cheese samples, kappa-carrageenan gum was applied at three levels (0, 0.03 and 0.06%) and transglutaminase was added at 2 levels (0 and 0.5 unit/g of protein). The low-fat sample without the gum and enzyme addition was considered as the control. All samples were evaluated in terms of sensory, textural and microbial characteristics after 1, 15 and 30 days of production. According to the results, the addition of gum caused a significant reduction of cheese hardness, while enzymatic treatment had adverse effect and it increased this parameter (p<0.01). Addition of 0.03% of gum resulted in the higher taste and texture quality, but the sensory attributes of low-fat UF-cheese samples decreased at the higher level, i.e. 0.06%. Furthermore, results showed that enzymatic treatment caused a substantial reduction on lactic acid bacteria (LAB) count, while gum addition had no effect. Overall, as the time of storage increased and until the 15th day of storage, all the sensory scores, the cheese hardness and the count of LAB increased while at the end of 30th day of storage, all these parameters significantly decreased. In conclusion, according to the sensory evaluation and texture results, the low-fat UF-cheese containing 0.03% carrageenan treated with transglutaminase was selected as the best sample.

Nowadays, the increasing demand for healthy foods has led to application of natural ingredients such as fruits in the formulation of food products. In this study, date waste (grade two) has been used in the formulation of a kind of nutritious jelly candy (up to 30%) with substitution of agar gum instead of gelatin (0, 15, 25 and 35%). Then physicochemical properties (moisture, dry matter, total ash, water activity, and color indices), texture characteristics (hardness, adhesiveness, springiness, stringiness and fracturability) and sensorial properties of the samples were analyzed and one-way ANOVA test at significant level of 95% was used for statistical analysis. The result showed that addition of date puree into jelly candy formula decreased moisture content, L* and b*, significantly (P<0.05) while total ash, a*, adhesiveness and stringiness showed an increasing manner (P<0.05). But effect of adding date puree on water activity and other texture characteristics including hardness, springiness and fracturability was not significant (P>0.05). Substitution of gelatin with agar (to 35%) resulted to decrease in moisture content and increase of total ash, color parameters and texture characteristics (P<0.05) while its effect on the other texture characteristics and water activity was not significant (P>0.05). The result of sensory evaluation indicated that the jelly candy containing 100% gelatin (agar free) recognized as the best specimen because of obtaining the suitable physicochemical properties and desirable texture.

Bioactive peptides are actually specific protein parts that, in addition to nutritional value, have positive effects on body function and conditions that lead to health effects. The combined use of pretreatment and enzymatic hydrolysis causes changes in the physical and chemical properties of hydrolyzed proteins. Microwave pretreatment is a well-known strategy to increase the accessibility of hydrolysis-sensitive bonds, facilitating enzyme cleavage sites and exposure to proteases. The aim of this research was to investigate the effect of hydrolysis time and also the effect of microwave pretreatment on enzymatic hydrolysis of edible mushroom (Agaricus bisporus) protein by trypsin enzyme to produce antioxidant peptides. To conduct this research, first, edible mushrooms were turned into powder after purchase from the market and conducting related processes. In this research, hydrolyzed edible mushroom was produced using trypsin enzyme without pretreatment and with microwave pretreatment at different powers of 120, 200, and 280W and time intervals of 30, 60, 90, 120, 150, 180 and 210 minutes. The antioxidant properties of the hydrolysed samples (DPPH radical scavenging activity, iron chelating power, iron ion reduction power and total antioxidant activity) were evaluated and compared. The results showed that in most of the experiments, pretreatment with microwaves decreased the time of obtaining and increased the antioxidant capacity of the samples, so that the samples pretreated with microwave power of 120W showed higher antioxidant power compared to the other treated samples. In all antioxidant tests, the sample pre-treated with microwave with power 120W and hydrolysed at 90minutes showed higher antioxidant performance, and therefore it is considered as suitable treatment.

In this study, the effect of nanoparticles on oxide at three levels of 1, 3 and 5% was added to polylactic acid and chitosan nanocomposites and the results of its SEM (electron microscope) evaluation were evaluated and showed films containing polylactic acid and chitosan. It had an irregular and compact structure and with the addition of nanoparticles on oxide, it had a regular and cohesive structure. And water vapor permeability showed a significant effect (P <0.05). The results of histometry showed that with increasing the concentration of nanoparticles, the tensile strength of the film and the nanocomposite coating was significantly lower than the control treatment (P <0.05). Also, large changes in length to break point did not show a statistically significant difference. The results of tissue stiffness of this study also showed that during the 15-day storage time, the test treatment had the highest amount of stiffness. The effect of film and coating of nanocomposites based on polylactic acid and chitosan containing nanoparticles on zinc oxide on microbial properties indicated that during the shelf life of bread containing polylactic acid and chitosan dimers has an inhibitory effect on fungal growth by increasing nanoparticles on zinc oxide. Increases significantly. It also showed that the shelf life of seven sliced ​​toast containing the mentioned variables was higher at 5% level compared to the control treatment.

Excessive use of antibiotics in the animal husbandry causes the accumulation of their residual amounts in food of animal origin such as dairy products. Since the consumption of these foods has a negative effect on human health, authorized organizations such as the European :union: have set maximum residue limits (MRLs) for antibiotics in food of animal origin. This research aimed to present a magnetic ionic solvent based extraction procedure for preparation and preconcentration of tetracycline, oxytetracycline and enrofloxacin residues in cheese samples and their determination by high-performance liquid chromatography equipped with a diode array detector. For this, the effect of various parameters on the extraction efficiency was investigated and optimized. The results showed that the residual amounts of oxytetracycline and tetracycline in 4 and 5 samples of the tested cheeses, respectively, were determined above the permissible limits. Enrofloxacin residue was not found in any of the samples. From the advantages of the proposed extraction method, we can point out the high separation power and the possibility of highly sensitive analyzing of mixed analytes, so that under optimized conditions, the recovery percentage ranges were 80-91. The limits of detection and quantification were respectively less than 1.8 and 6 ng/g, which is much lower than the MRLs set for target antibiotics in cheese (100 ng/g).

In this study, chitosan-coated nanoliposomes in ratios of 9-1, 8-2, 7-3 and 6-4 lecithin-cholesterol, were prepared using thin-film hydration method, as a practical delivery system for encapsulation of caffeine. Then, the particle size and zeta potential were measured to determine the characteristics of the produced particles. Average particle size (average hydrodynamic diameter) and particle size distribution for different lecithin-cholesterol ratios were in the range of 135.5-533.5 nm and 0.31-0.41, respectively. Zeta potential values were also obtained in the range of +40.96 to +50.5. After determining the encapsulation efficiency, FTIR method was used to investigate possible reactions between caffeine and nanoliposome wall materials. The morphology of chitosome with 9-1 ratio of lecithin-cholesterol loaded with caffeine, was shown by scanning electron microscopy (SEM). The stability of the chitosomal sample with a ratio of 1-9 lecithin-cholesterol was evaluated through visual observation of precipitation formation and calculation of the amount of release of encapsulated caffeine during 60 days of storage at ambient temperature. The results obtained in this research showed that nanochitosomes are an efficient system in maintaining and releasing caffeine.

The purpose of this study is to investigate the chemical and microbial properties of date syrup during different stages of production line from the raw material to the final product. The amounts of total soluble solids, pH, acidity, total and reducing sugars, polyphenolic compounds, antioxidant activity and microbial count were measured and the type of microorganisms was determined based on phenotypic characteristics in different stages of production. The obtained results showed that during the stages of juice clarification and concentration, pH gradually decreased and acidity, total sugar, reducing sugar and total solid matter increased and reached their maximum in the syrup. Comparison of traditional syrup with factory produced syrup showed more pH and acidity, total and reducing sugar, total soluble solid, polyphenolic compounds and lower antioxidant activity for traditional syrup compared to the produced one. In general, the content of polyphenolic compounds and antioxidant activity gradually decreased in different stages of production, so that date syrup (279 mg of gallic acid per 100 grams of sample and 33%) indicated higher content of polyphenolic compounds and antioxidant activity than dates (388 mg of gallic acid per 100 g of sample and 57%). The results of the microbial test showed the lowest microbial load for the produced syrup compared to dates and different syrups. However, the presence of B. licheniformis in the syrup makes the product sour, in this regard finding a suitable solution to increase the shelf life of the product seems necessary. The traditional syrup showed a lower microbial load than the produced syrup, although B. licheniformis was observed in the traditional syrup despite the high heat treatment. Based on the obtained results, the date syrup was free of coliforms, which indicates maintaining the hygienic principles of manufacture during the production line.

Phytosterols are among the most important plant sterol compounds. This study was conducted to identify and determine the amount of phytosterols in distributed yogurts in Tehran by gas chromatography method without derivatization. A total of 60 yogurt samples, including 20 pasteurized high-fat yogurt samples, 20 pasteurized cream yogurt samples, and 20 traditional high-fat yogurt samples, were collected randomly from dairy product supply centers in Tehran from January to March 2022. Then, the amount of cholesterol and four phytosterol compounds including brassicasterol, campesterol, stigmasterol, and beta-sitosterol in yogurt samples were determined using gas chromatography assay without derivatization. The results showed that the total sterols in high-fat, creamy, and traditional yogurt samples were 504.08±55.79, 816.21±51.87, and 332.8±41.22  mg/100mL, respectively. The highest and lowest percentage of cholesterol belongs to cream (%54.75±065) and traditional yogurt (%46.57±0.65), respectively(p<0.05). Also, the highest percentage of phytosterol belongs to traditional yogurt(%54.75±065) and there was a significant difference with other yogurts(p<0.05). The results also showed that the total phytosterols were more than the permissible limit of the national standard (3%) in all samples. According to the results, phytosterols are used in various yogurts distributed in Tehran, which is against the national standard of Iran. Therefore, periodic and regular evaluation of phytosterols in distributed yogurts should be done throughout the year by regulatory bodies and prevent the violation of consumers' rights.

The aim of this study was to isolate thermostable amylase producing bacteria from starch-rich wastewater of one of the canning factories and then molecular identification of these isolates. In addition, the thermostable amylase extracted from the bacterium was investigated for the optimum temperature and pH of enzyme activity. In this study, 14 heat-resistant microbial isolates were isolated from wastewater and only two isolates had amylase activity.  Molecular identification of isolates based on amplification of 16S rDNA gene by B27F and U1492R primers and then sequencing of PCR product confirmed the presence of Bacillus pumilus and Bacillus safensis. The results showed that the optimum temperature and pH of amylase activity were 60°C and 7, respectively, and Bacillus safensis 7.67 (U/ml) had more amylase activity than of Bacillus pumilus 6.33 (U/ml).

Ultrafiltrated (UF)-white cheese is almost a new generation of white-cheeses that is produced throughout ultrafiltration process. This cheese has a soft and spreadable texture and is distributed in the market after a short storage period. Lactulose is a prebiotic compound that in addition to its positive effect on the growth of probiotic bacteria, its beneficial health effects on human well-being is proved. In the current research, synbiotic cheese samples were produced with the usage of demineralized ultrafiltrated whey powder (DUWP) at 3 levels of 0, 1 and 2%, lactulose at 2 levels of 0 and 1%, and bifidobacterium bifidum as probiotic bacteria. Experimental samples were analyzed and tested for physicochemical analysis including pH, acidity, moisture, syneresis, fat, protein and soluble nitrogen to total nitrogen ratio (TSN/TN) during 60 days of storage at 4 ◦C. Results revealed that addition of DUWP and lactulose, except for protein, had significant effects on the other tested parameters. In addition, the time of storage period had noticeable impact on all the examined physicochemical properties (P<0.01). Based on the results of this study, it was found that the best UF-white synbiotic cheese could be produced with the usage of 1% of each DUWP and lactulose powders.

The aim of this study was to see how alkaline salts of sodium carbonate and potassium carbonate, as well as peanut skin extract, affected the qualitative qualities of fried coated peanuts during shelf life, as well as the chemical properties of the oil used in the frying process.Control coated peanuts with no alkaline salts or peanut skin extract, as well as additional samples with varying percentages of two alkaline salts, sodium carbonate (0.10, 0.12, 0.14) and potassium carbonate (0.16, 0.18, and 0.20)next to each other or along with 0.02% peanut skin extract.Following the production of samples, the peroxide and anisidine indices, oil absorption rate, colorimetry, and sensory assessment of peanuts were assessed.The utilized oil's iodine, soap, peroxide, anisidine values, polar compounds, and acidity were also studied.The addition of alkaline salts reduced oil absorption in peanuts significantly (p< 0.05).Lower peroxide and anisidine values were detected in samples containing peanut skin extract in addition to alkaline salts (p<0.05).Increasing the concentration of alkaline salts significantly led to a decrease in brightness, an increase in redness, yellowness, and ΔE in coated peanut samples (p<0.05).The sensory evaluation scores decreased as the concentration of alkaline salts increased, but the use of concentrations of 0.10% sodium carbonate and 0.16% potassium carbonate significantly improved texture crispness and overall acceptability compared to the control (p<0.05).There was no significant difference in other sensory indications as compared to the control.Chemical analysis of used frying oil revealed the same results for all samples, and alkaline salts and peanut skin extract had no effect on the oil's quality.The iodine and soap values of the oils used to fry all peanut samples declined, whereas acidity, peroxide and anisidine values increased.According to the results, it was proposed to coat peanuts in the frying process with 0.10% sodium carbonate,0.16% potassium carbonate, and 0.02% peanut skin extract.

Olive oil is a unique edible oil that has attracted attention due to its high levels of monounsaturated fatty acids, pleasant taste, good stability, and special health benefits. In this study, the quality of virgin olive oils from the Arbequina, Mari, Shengeh, and Zard cultivars in the Tarem region was investigated, and the parameters of sterols, acidity, peroxide value, and iodine value were evaluated. Gas chromatography was used to determine and identify the sterols. The results showed that the amount of sterols in virgin olive oils from the Arbequina, Shengeh, Zard, and Mari cultivars differed significantly at the 5% level. The most abundant sterols found in all cultivars were beta-sitosterol, delta5-avenasterol, and campesterol. The free acidity level in the Mari cultivar had the highest amount, while the Arbequina cultivar had the lowest amount. The highest peroxide value was observed in the Zard cultivar, while the lowest was observed in the Mari cultivar. Finally, it can be concluded that the quality parameters evaluated for the Arbequina, Shengeh, Zard, and Mari cultivars were within the allowable standard range, and there was no significant difference in quality among these cultivars.

Strawberry is a non-climacteric fruit, but its high post-harvest respiration rate results in a rapid spoilage at room temperature. The aim of this study was to evaluate the application of biodegradable coating based on Lepidium sativum seed mucilage in combination with Cinnamomum zeylanicum essential oil in post-harvest protection of strawberry fruit at 4 °C. Strawberry coating treatments included control sample, mucilage without essential oil, mucilage containing 0.5% essential oil, mucilage containing 0.75% essential oil, and mucilage containing 1% essential oil. Physicochemical (total soluble solids, pH, acidity, and hardness), microbial (mold and yeast), and sensory (color, odor, texture, and overall acceptance) properties of the fruits were studied on days 1, 4, 7 and 10 of storage. The treatments containing essential oil had a positive effect on post-harvest quality of strawberries. Although the quality of samples decreased by storage time, compared with the control sample, mucilage coating containing 1% essential oil prevented severe changes in acidity, pH, hardness, fungi count, and sensory properties of the samples during the storage period and it was selected as the best treatment. In general, samples coated with L. sativum seed mucilage containing C. zeylanicum essential oil showed the highest overall acceptance compared to the control sample due to low microbial load and preservation of texture and flavor compounds. Therefore, the edible coating based on L. sativum seed mucilage and C. zeylanicum essential oil can be used to increase the shelf life of other food products.

Encapsulation is a process to protect bioactive compounds against unfavorable environmental conditions in order to increase their stability and bioavailability. Regarding the existence of bioactive compounds in grape pomace and flaxseed oil, the aim of this research was to encapsulation of grape pomace (Vitis viniferae cv. Rash (and flaxseed oil with different ratios of maltodextrin and gum tragacanth (1:1, 1:2, 2:1) using a spray drier and evaluation of the quality properties of obtained microcapsules. The produced microcapsules were analyzed in terms of microcapsulation yield, solubility and humidity contents, total phenolic contents, antioxidant activity, the interaction between wall and core materials and microstructure. According to the results, there were no significant differences between the microcapsules in terms of humidity and solubility contents (P<0.05). The highest microencapsulation yield, total phenolic contents and antioxidant activity were observed in the microcapsules produced with equal ratios (1:1) of maltodextrin and gum tragacanth. While the spherical shape was observed by scanning electron microscope for all of microcapsule samples, the microcapsules produced with equal ratios (1:1) of maltodextrin and gum tragacanth had a more compact and homogeneous structure. FT-IR analysis also confirmed the creation of new interactions between the wall and core materials of the obtained microcapsules. The results of the present research showed that using maltodextrin and gum tragacanth as wall material in an equal ratio (1:1) had a proper performance in order to microencapsulation of grape pomace and flaxseed oil.

In this research, the effect of inlet air temperature (130 and 160°C), type and composition of carriers (maltodextrin, Arabic gum and whey protein concentrate (WPC)) on yield, moisture, bulk density and impact, solubility, wettability, flowability (angle of repose) and hygroscopicity of spray dried borage flower extract were investigated. In all tests, atomizer speed, feed flow rate, feed temperature, and atomizer air pressure were kept constant at 18000 rpm, 10 ml/min, 30 ± 1 °C, and 4 ± 0.1 bar, respectively. The minimum significant difference was calculated at less than (P<0.05) using SPSS software. The results showed that the highest production efficiency (48%) was achieved in dried samples with the combination of maltodextrin and WPC. While the use of protein as a carrier led to a decrease in the amount of moisture, mass and impact density, solubility, wettability and hygroscopicity of particles. The optimization results using the estimated models indicated that the highest solubility and the lowest hygroscopicity are created in the powder dried at 130 degrees Celsius with maltodextrin and arabic gum carriers.