فصلنامه پژوهش و نوآوری در علوم و صنایع غذایی
سال دوازدهم شماره 1 (بهار 1402)

The aim of the present study was to evaluate the efficiency of sulfur dioxide release sheets on the basis of acetate cellulose film to control the growth of molds, especially botrytis cinerea, during the storage period of kiwifruit. For this purpose, the storage of kiwifruit inoculated with botrytis cinerea in the presence of one and dual sulfur dioxide releasing sheets (containing 30 and 50% metabisulfit salts, respectively) on the acetate cellulose bed was investigated. After 15 days of storage (9 days in cold store and 7 days in ambient temperature), the least bursting and crushing (4.5%) was obtained in the presence of single-stage sheets that were placed on the surface and bottom of the packages. Also, in the ninth day, mold was not observed in the 60% of packages in the presence of sulfur dioxide releasing sheets. On the 15th day, the amount of total sugar, acidity, firmness, residual sulfur, and soluble solids in packaged kiwis in the presence of two dual releasing sheets placed on the surface and bottom of packages were, respectively, 9.9 g/100 g, 1.09%, 4.75 N, 0.24 mg/g and 12.21%. In general, it can be said that sulfur dioxide releasing sheets have an effective function on cold storage in increasing the shelf life of fruits, especially fruits that are attacked by gray mold.

In the present study, hydrogel emulsion particles made by emulsion templating method were used in order to encapsulate a-tocopherol. An oil-in-water-in-oil emulsion was used as mold to make microgel particles. The aim of this study was to investigate the effect of partial replacement of whey protein with iota-carrageenan (0, 0.2 and 0.4 wt%) on emulsion properties, hydrogel particles and release of a-tocopherol. The results showed that the introduction of iota-carrageenan in the formulation increased the apparent viscosity of the simple emulsions, droplet size increased from 2.69 μm in emulsions containing whey protein alone to 2.95 and 2.71 μm in emulsions containing 0.2 and 0.4 of iota-carrageenan. Replacing 0.2 and 0.4% of iota-carrageenan reduced the zeta potential from -43.93 mV to -46.56 and -46.68 mV, respectively. The introduction of iota-carrageenan in the formulation also reduced the particle size and reduced the encapsulation efficiency of a-tocopherol in hydrogel emulsion particles. Addition of iota-carrageenan to the formulation of hydrogel particles reduces the release rate of a-tocopherol in simulated gastric fluid from 30.36% in particles containing whey protein alone to 28.90 and 28.22% in particles containing 0.2 and 0.4% of iota-carrageenan, respectively. The results of this study showed that replacing part of the whey protein with iota-carrageenan improved the release and delivery of the lipophilic bioactive compound to the intestine in hydrogel emulsion particles.

In this study, a non-dairy beverages based on almond, coconut and soy milk was produced in combination with runner bean flour in both germinated and non-germinated states on the physicochemical and sensory properties of the samples was investigated. To prepare vegetable milk, soy beans, almonds and coconuts (20, 25 and 25 g, respectively) are soaked in water at the ratio of 1:6, 1:4.2, and 1:4, respectively, for 12 h at room temperature and they were mixed in a mixer. All sprouted and unsprouted bean powders were mixed separately with 100 mL of vegetable milk to prepare sprouted and unsprouted soy, almond and coconut milk drinks in a weight of 6 g, and finally the drinks were evaluated in terms of chemical properties (acidity, pH, antioxidant capacity, and sugar), viscosity and Sensory acceptance was investigated. The results showed that the germination of runner beans increased the factors of acidity, TEAC, phenolic content and sensory properties and decreased pH. Increased acidity and decreased pH were higher in non-dairy beverage with germinated beans than in samples containing non-germinated beans. The highest viscosity in the sample of almond drink contained germinated and non-germinated beans. Almond milk drink containing sprouted beans and coconut milk drink containing sprouted beans had the highest sugar content. TEAC and phenolic content were higher in coconut milk samples containing germinated beans. The results of sensory properties also showed that beverage based on coconut milk containing germinated beans and almond milk containing germinated beans were more popular among consumers.

In this study, interaction between WPC and OSAS as a function of pH (3, 4, 5 and 6) and biopolymers ratio (1:2, 1:1 and 2:1) at total concentration of 1% w/w was investigated by measuring the structural (turbidity, particles size, Zeta potential, viscometery, FTIR) and morphological (SEM) properties. Maximum zeta potential was observed at 2:1 biopolymers ratio and pH=3. With increasing pH and decreasing ratio of WPC:OSAS, zeta potential value decreased. At ratio 1:2 and pH 6 minimum zeta potential was gained. Minimum particles size was observed at ratio 1:2 and pH=6 (0.819 µm) in which with decreasing pH to 4 and increasing ratio up to 2:1, it was maximized (2.260). Turbidity results was in accordance with particles size measurements and maximum and minimum results was observed at the same points. At ratio 1:2 and pH=4, maximum viscosity was observed (1.301 mPa.s). Reducing the ratio and increasing pH led to minimum viscosity at pH=6 and ratio 2:1 (1.147 mPa.s). In all measured characters, there was significant difference between control (WPC) and complex samples. FTIR study revealed that by complexation between WPC and OSAS, amid II peak was weakened and carboxylated and OSA group's peak were removed. SEM images showed that with formation of electrostatic complex, spherical structures of WPC and OSAS was changed to porous network and sheet structures.

Due to its unique role, phycocyanin pigment extracted from the cyanobacterium Spirulina platensis can play an important role in enriching traditional cheeses. In this study, the amount of protein, fat, ash, moisture, β-carotene and pH of fortified cheese with different concentrations of phycocyanin pigment were determined. In addition, the counting of bacteria was done along with the assessment of antioxidant properties. Also, gas chromatography-mass spectrometer GC-MS test was performed to identify volatile compounds during 1, 3, 7, 14 and 21 days. The results of tests showed that the amount of fat, moisture, pH and 1,1-diphenyl-2-picrylhydrazyl (DPPH) of fortified cheeses has decreased significantly compared to the control. Also, the amount of protein, β-carotene, ferric reducing assay power (FRAP) and nitric oxide trapping increased significantly compared to the control. Sensory evaluation had also significant increase in satisfaction, except for the sense of smell compared to the control. In addition, no signs of Escherichia coli and Staphylococcus aureus were found during different days. However, the presence of coliform bacteria was evident from 7 to 21 days in enriched and control cheeses. Also, the results of volatile compounds obtained from GC-MS test in control cheese and enriched cheese with 1% phycocyanin pigment show the presence of compounds with antimicrobial properties that played an important role in the shelf life and quality of cheese. It is hoped that the results of this study will be the basis for empowering the food industry in using pigments obtained from cyanobacteria.

After testing and verification of resistance to gastrointestinal conditions confirming the strain selected to prepare probiotic fermented goat milk, 0.5 g of Lactobacillus plantarum (PTCC 1058( and Lactobacillus casei (PTCC 1608( were inoculated into 200 mL of goat milk sample. Then, 2, 4, and 6% of barley malt extract were added to the treatments to evaluate the effects of malt extract on the survival and activity of probiotic bacteria. Sample tests (including physicochemical, colorimetric indices, viscosity, antioxidant activity, and general acceptance) were evaluated on production days 7, 14, 21, and 28. The results showed that increasing the concentration of malt extract increased the content of soluble proteins, antioxidant activity, acidity, and decreased pH in all treatments increased (P<0.05). Also, adding malt extract and increasing its concentration increased the viscosity and brix on the day of production, but during 28 days, these parameters decreased (P<0.05). The color indices showed L* sample decreased and a* and b* increased with increasing the concentration of malt extract during storage (P<0.05). Evaluation of general acceptance of samples showed by increasing the malt extract concentration, treatment desirability declined. As well as, evaluation growth probiotic bacteria showed during the 7th day, due to the presence of sufficient nutrients, they significantly increased. Then the population of probiotic bacteria decreased (P<0.05). Generally, according to the results and sensory evaluation, probiotic goat milk containing 4% malt extract is the best sample, and recommend that consumed during the 7th day as the best time.

Vitamin C (L-ascorbic acid) is a basic nutrients and very effective antioxidant that acts as a natural preservative in fruits (such as Cucumis sativus). Aiming to maintain bioactive compounds (especially inhibition the dehydroascorbic acid formation) and preventing the spoilage development, the effect of edible coating types (I: control, II: Shiraz gum & III: Shiraz gum containing 1000 ppm Mentha piperita L. essential oil) and storage times (1, 8 and 16 days) on the auto-oxidation kinetics of vitamin C and its inhibitory role on inhibition of bacterial/fungal growth of Cucumis sativus at +4 °C, was evaluated. The results indicated that the variation rate of Cucumis sativus vitamin C degradation during storage period follows the zero-order kinetic reaction (the highest R2/P(%) ratio). The lowest growth rate of mesophilic bacteria (6.95), mold (3.21) and yeast (6.04) of Cucumis sativus in (log10 CFU/g) observed after 16 days of storage in sample (III) that corresponding to the lowest rate of vitamin C degradation. The half-time values (t1/2) of vitamin C degradation rate showed that, the best shelf-life of Cucumis sativus (in the studied conditions) was ~10 days, aiming to maintain the most nutritional properties. Generally, the findings of present research can be useful for monitoring the shelf life of Cucumis sativus kept in cold stowage.

The present study aimed to prepare powder from silver carp fish bone applying alkaline method and investigate its nutritional, sensory, and microbial characteristics. In this research, calcium carbonate was used as a control. The amounts of protein (18.51%), fat (5.11%), moisture (5.58%) and ash (70.82%) were determined in the fish bone powder. The efficiency of powder preparation was determined to be 66.98%. Unlike fish bone powder, the mineral elements silicon, aluminum, barium, and chromium were not observed in the control sample. Phosphorus in bone powder (81580 mg/kg) was more than the control (310 mg/kg) (P<0.05). However, calcium in the experimental treatment was lower (325000 mg/kg) compared to the control (388000 mg/kg) (P<0.05). In terms of overall acceptance and color no significant difference was observed between experimental and control treatments (P<0.05). Among saturated fatty acids, monounsaturated and polyunsaturated fatty acids, respectively, palmitic acid (22.73%), elaidic acid (43.74%) and linoleic acid (7.35%) had the highest amounts in bone powder. Also, the total amount of essential amino acids including threonine, valine, lysine, isoleucine, methionine, histidine, and phenylalanine was 218.29%. The no microorganisms such as fungi, Escherichia coli, and Salmonella in the treatments were observed. Since bone powder can be produced in large quantities from different types of fish and is rich in nutritional compounds, it is suggested to the food industry for enriching food products.