مجله علوم غذایی و تغذیه
سال بیستم شماره 1 (زمستان 1401)

Among the pigment-producing microorganisms, Monascus purpureus is important for controlling diabetes and preventing and reducing fat due to the production of red and orange pigments with therapeutic properties such as anti-cancer, anti-inflammatory.

In this study, the effect of replacement of potato starch waste (RPSW) (20-100%), sodium chloride (6-14 g) and thermal stress time of spore suspension (TST) (50-90 seconds) on the growth of M. purpureus and production of red and orange pigments at 30 ° C in submerge culture were studied by the central composite design at 95% confidence level.

The results showed that increasing the RPSW by up to 50% significantly reduced red and orange pigments and increased biomass production (p <0.05). On the other hand, increasing the TST of spore suspension to 73 seconds and increasing the amount of sodium chloride at the concentrations above 9 g / l significantly increased the production of biomass and red and orange pigments (p <0.05). At the two optimal point with the RPSW (20.3, 42.5) (%), TDT spore suspension (65, 81)(s) and concentration of sodium chloride (12, 6) (g/l) respectively, the biomass (g / l), red and orange pigments (OD/l) (5.24, 4.55 and 3.5) and (4.55, 4.37 and 5.4), respectively, were obtained.

The results of this study showed that since the replacement of potato starch waste increased biomass production but reduced the production of red and orange pigments Monascus purpureus, its amount should be used optimally in culture to achieve the best productivity.

In recent years, the use of citrus peel essential oil as a natural preservative in foods has been widely considered. There are several methods to extract the essence oil of orange peel, one of which is the use of ultrasound. The objective of this study was to evaluate the extraction conditions of essential oil by ultrasound method from the peel of Thompson cultivar using the response surface methodology.

Independent variables included ultrasound intensity, time and process temperature at three levels of 20, 60 and 100%, 5, 10 and 15 min and 25, 35 and 45 ͦ C were studied, respectively. Efficiency of extraction, total phenolic compounds, DPPH and inhibitory of orange peel essential oils against Aspergillus niger fungus were determined.

The optimal conditions for extracting the essential oil of orange peel were sonication intensity 60%, processing time and temperature of 19 min and 35 °C respectively. At this optimum condition, efficiency of extraction, phenolic compounds and DPPH value of the orange peel essential oils were 13.09%, 42.16 mg/100g and 55%, respectively. The experimental values were in a good agreement with the predicted values. Also, at the optimal conditions, the minimum inhibitory concentration (MIC) of the orange peel essential oils was 18.5 mm and potassium sorbate was 18.3 mm. Therefore, orange peel essential oil at a concentration equal to potassium sorbate (1000 mg/ml) has antifungal activity against Aspergillus niger.

The present study revealed that the essential oil of orange peel has a potential source of active ingredients like polyphenols that are well-known for their antioxidant properties. Ultrasound extraction is an effective technique for extraction of these compounds. Also orange peel essential oil can be used in foods instead of chemical and synthetic antioxidants and preservatives.

Recent researches have indicated that phytochemicals compounds are important as antioxidants and antimicrobials in food. The use of nano carrier-based formulations in controlled release and protection of these compounds is an effective way to maintain these properties. In this study, Iranian shallot with the scientific name of Allium stipitatum Regel has been used due to the unique phytochemicals of this plant. This study aimed to prepare and characterize the synthesized nano-phytosomes containing shallot phytochemical compounds and their antimicrobial effects in comparison with shallot extract.

An aqueous-alcoholic extract of shallot was obtained from dried shallot. The structure of the nano-phytosome was prepared by the thin layer hydroxylation method. The structure of the synthesized nano-phytosomes was examined by SEM microscope and dynamic light scattering DLS. Finally, antimicrobial properties were evaluated on Escherichia coli bacteria. Antibacterial assay was performed using MIC and MBC tests for shallot extract and nano-phytosome samples at successive concentrations of the sample.

Structure study of nano-phytosomes indicated the spherical shape and size between 5-10 nm of nano-phytosomes. Dispersion of nano-phytosomes in the colloidal medium was observed in a suitable form and PDI index equal to 0.586. The results of microbial tests showed that the effect of nano-phytosomes on bacteria was significantly greater than the antimicrobial power of nano phytosomes compared to shallot extract on Escherichia coli samples.

This study can prove the effect of shallot extract nano-phytosome as an antimicrobial nanobiostructure.

Shrimp waste might be used as the cheapest raw material to extract the carotenoid pigments, astaxanthin and employed to replace the synthetic dyes. In the present study, effective factors on extraction of astaxanthin super antioxidant from white shrimp was evaluated.

In this study, extraction with solid material ratio (cooked/ dried shrimp/ mill/ sieve) to ethanol solvent (g/ml) in 3 levels of one to five, one to seven and one to nine, with stirring time of 1, 5 and 10 minutes in ultrasonic bath was performed in 3 levels of 10, 20 and 30 minutes and centrifuge temperature 4, 12 and 21 ºC in triplicate order. After evaluating the carotenoid extraction efficiency of dry and wet wastes in the spectrophotometer, the best extraction method was selected by data analysis using SPSS.20 software using Duncan's multiple range method, finally, astaxanthin treatment 1 (cooked/ Dry/ mill/ sieve) and treatment 2 (crude/ mill) were optimized, purified, measured and identified by HPLC and the optimal treatment was selected.

Experiments showed that the sample to solvent ratio of 1: 5 and one minute stirring time, 10 minutes ultrasonic and 21 ° C centrifuge are suitable for optimal extraction. Data from HPLC analysis also showed that astaxanthin was extracted from treatment 1, 3 mgastaxanthin/gextract and treatment 2, 2.7 mgastaxanthin/gextract.

Shrimp waste might be used as an available and economical raw material to extract carotenoid pigments to replace the synthetic dyes and antioxidants in the food industry.

Today, mushrooms are used as a common food source in many countries. Edible mushrooms have a low shelf life. The aim of this study was to use modified atmosphere packaging with different ratios on the shelf life and nutritional value of button mushrooms.

 In this research, the mushroom samples were placed in polypropylene-covered packages, and the packaged were filled with gas mixtures of 100% oxygen, 25% oxygen with 75% nitrogen, 50% oxygen with 50% nitrogen, and also 25% oxygen, 25 the percentage of carbon dioxide and 50% of nitrogen were filled and packed. The control sample was button mushroom packed with polypropylene cover and without modified atmosphere (control).The investigated characteristics included the percentage of weight loss, the percentage of free amino acids, the percentage of ascorbic acid, the concentration of polysaccharides, the intensity of respiration, the ripening index, the browning coefficient, colorimetric characteristics and sensory characteristics on the first, fifth, tenth and fifteenth days of storage at 4ºC was evaluated.

 The results showed that the weight loss indexes, free amino acids, ascorbic acid and brightness index of button mushroom significantly (p≤0.05) decreased during storage, and respiratory rate, browning coefficient, jaundice, and redness significantly (p≤0.05) increased. All sensory indicators of texture, spoilage and bad smell, appearance color and overall acceptance also faced a significant decrease during 15 days of packaging (p≤0.05). Among button mushroom treatments, gaseous conditions of 25% oxygen, 25% carbon dioxide and 50% nitrogen had the least amount of changes during the storage time compared to the first day and showed a higher ability to protect button mushroom, and the control treatment had the highest Drop rate over time. Also, the treatment of 25% oxygen with 75% nitrogen and the treatment of 50% oxygen with 50% nitrogen did not show significant differences during 15 days of storage (p>0.05).  

Finally, packaging with gaseous conditions of 25% oxygen, 25% carbon dioxide and 50% nitrogen was introduced as the optimal treatment.

 Rice parboiling process, hydrothermal process of paddy and / or brown rice are among the important processes in the rice industry and include three main stages of soaking in water, evaporation and drying. Due to the increased digestibility of grains following gelatinization, achieving a suitable level of gelatinization n the soaking stage is a basic and essential step in parboiling process.

In this study, Fajr rice varieties were collected from agricultural fields in Gorgan and soaked at temperatures of 35, 45, 55 and 60 °C. Sampling was performed at different time. The gelatinization temperature of rice grains was modelled by calculating the mass permeation constant (Def) of paddy water with Fick model. Then, the approximate temperature of grain gelatinization was determined by Arrinius equation.

The data obtained from adsorption had a good fit in terms of dry moisture content under laboratory conditions with Fick equation and this model properly explained the water absorption behaviour of the samples. Soaking at higher temperatures resulted in faster water absorption. The water adsorption behaviour of the seeds showed that at a temperature of 60 ° C, the seeds do not tend to reach equilibrium moisture and a downward trend was observed in their diagram. Also, with increasing temperature, the Def increased. The Def brown grain was 2.7 times that of paddyو while The Def withe grain was 4.1 times that of brown bean. The R 2 and RMSE obtained for each soaking temperature condition showed that Rice peeling until the brown grain reached and then soaking the brown grain (instead of paddy) could be more effective.

 Using graph and Arrhenius equation, the optimal soaking conditions of Fajr grains for 2 hours at 45 °C were determined.

Cocoa milk is one of the most popular non-fermented dairy products, but due to its high levels of sucrose, it might cause diabetes and tooth decay in children. Due to the fact that today the tendency to consume natural foods is increasing with low calories and high shelf life, therefore, replacing sucrose with other sweeteners, especially natural ones, will be important. In this study, the aim is to optimize and achieve the highest percentage of viscosity and overall acceptance as well as reducing the amount of sedimentation and particle size that is one of the important quality indicators of cocoa milk in consumer acceptance.

For this purpose, treatment was performed based on cocoa milk formulation and based on the highest level of response. Independent variables included inulin (2 to 8%), chia seed gum (0.1 to 0.5%), stevia (50 to 100%) and whey protein concentrate (1 to 3%) and response variables, consisting of viscosity, particle size, sediment percentage and overall acceptance were considered. The functional relationship between the parameters affecting the cocoa milk formulation was determined using the Box Behnken experimental design.

Based on the selected models, the optimal formulation was selected by the software consisted of 99.7% inulin, 70% stevia, 0.346% chia seed gum and 1% whey protein.

The presence of inulin, stevia, chia seed gum and whey protein in cocoa milk formula improved the effective properties such as increasing viscosity, reducing sedimentation and cocoa milk particle size in promoting marketability and product acceptance by consumers. Therefore health-promoting in cocoa milk formulation can lead to the production of useful products while maintaining quality and sensory properties.

Nowadays, the selection of probiotics has an important role in the development of the country's food industry and the production of probiotic dairy products is the main indicator of this progress on the other hand, the quality, sensory and viability characteristics of probiotics in manufactured products are the main problems of most industrial factories.

the effect of different concentrations of kombucha drink on the viability of Lactobacillus acidophilus, bifidobacterium bifidum, Lactobacillus Rhamnosus was studied and physicochemical and sensory characteristics of fermented milk were measured during 28 days of storing period at 5±1˚C. Different levels of Kombucha tea 0, 5, 10, 15 and 20 ml/L were added to probiotic fermented milk containing L. acidophilus, B. bifidum, L. Rhamnosus bacteria (Cfu/ml 107) .Viability rate of probiotic bacteria, pH, percentages of protein, acidity(Dornic), acetic acid, antioxidant compounds were measured during 3, 7, 14 and 28th of storing period at 4 ⸰C.

Results showed that higher amounts of kombucha cause higher content of protein, acidity, acetic acid and antioxidant activity. The average amounts of theses parameters were respectivly 0.12,0.02, 15.694 and 0.16. however, pH and viability of probiotic bacteria significantly decreased during the storage period(p<0.05) and average amounts of these parameters were respectively0.79 and 0.046, However, the mentioned indices were higher than the acceptable standard of probiotic products.

the addition of kombucha up to 5% could be more effective in improving sensory characteristics. Hence, a treatment containing 5% of kambucha was selected as the best among others.