جستجوی مقالات مرتبط با کلیدواژه « physicochemical characteristics » در نشریات گروه « پزشکی »

 Functional foods refer to foods enriched with substances such as vitamins, proteins, fibers and probiotics with the intervention of technology.

Paraprobiotic cells were achieved using thermal method. Probiotic and paraprobiotic yogurt were produced from low-fat milk and samples were stored at 4 °C for 7 d. Then, microbiological and physicochemical (pH, acidity, syneresis, water holding capacity, color and texture) characteristics of the samples were assessed on Days 0 and 7.

Until the end of the storage in the two samples, pH decreased, acidity increased, syneresis decreased and water holding capacity increased. Live and killed Lactiplantibacillus plantarum cells included similar effects on the yogurt color. Texture analysis showed no statistically significant differences (P ˃ 0.05) between the two samples and all three parameters of hardness, consistency and adhesion increased in the two samples. Results of counting live cells showed statistically significant differences (P < 0.05) between the two yogurt samples; however, number of the live cells in the two yogurt samples increased until the end of Day 7.

Paraprobiotic cells can be used to produce yogurts due to their health and technological advantages, long shelf life, simplicity of work, lack of side effects and sensitivity to the environmental conditions. It seems that they can be used as appropriate alternatives to probiotics in development of functional yogurts. However further clinical studies should be carried out to verify health benefits of paraprobiotics.

The use of natural active compounds in edible films is a suitable approach for active packaging production. The objective of this study was to investigate physicochemical and antifungal characteristics of soy protein isolate edible films containing eucalyptus tannin extract.

Tannin extract was prepared from eucalyptus leaves and then added to soy protein isolate films in three concentrations of 1, 2.5 and 5%. The antifungal activity against Aspergillus niger was evaluated,, along with the assessment of moisture sorption isotherms using Guggenheim-Anderson-de Boer (GAB), model permeability to water vapor and antioxidant activity of the films by inhibiting DPPH free radicals.

The fitted moisture absorption experimental data demonstrated that the GAB provided accurate predictions of moisture absorption isotherms with a good fit to the water activity (R2 > 0.92). Based on the results of principal component analysis (PCA), three major components accounted for 96% of the variance of the physicochemical parameters. Antioxidant activity using the DPPH method increased significantly from 6.43 (in the control sample) to 56.92% (in the sample containing 5% tannin), while the vapor permeability decreased particularly at high loading contents of tannin, compared to the control films. Samples containing eucalyptus tannin included good antifungal activities against Aspergillus niger and increasing quantities of tannin in the samples led to significant increases in the inhibition of fungal activity (p < 0.05).

The use of natural additives such as eucalyptus tannin extract in biodegradable films can improve the functional performance of soy protein isolate film and help to increase the shelf life of food products due to their antifungal and antioxidant characteristics.

Breakfast-chocolate is high in fat and calorie; hence, its consumption is limited for people suffering from certain diseases such as obesity and diabetes. Therefore, replacement of fat and milk powder with compounds based on carbohydrate and protein with low digestibility can decrease calories of this product and made it consumable for patients with lactose intolerance.

Therapeutic diet breakfast-chocolate was produced by replacing maltodextrin and guar-xanthan gum with cocoa butter at 0–100% levels and replacing sesame and sweet almond meals with milk powder at 0–100% levels. Then, physicochemical, textural, rheological and microbiological characteristics of this product were compared with those of the control sample (containing cocoa butter and milk powder) during 60 d of storage using SPSS Software.

Results showed that maltodextrin and guar-xanthan replacement included significant effects (p < 0.05) on decreasing calories and fat content of diet breakfast-chocolate. Complete replacement of sesame and sweet almond meals with milk powder caused significant increases (p < 0.05) in the protein content of the final product. All samples of diet breakfast-chocolate on the Day 1 of production and Day 60 after storage included higher elastic modulus (G' ) values than the viscous modulus (G") within the temperature range with no significant differences, compared to the control sample.

Results of this study verified effectiveness of using fat substitutes such as maltodextrin and guar-xanthan gum and sesame and sweet almond meals as substitutes for milk powder in production of therapeutic diet breakfast-chocolate with similar qualities as commercial samples.

Greenhouse cucumber is one of the most important summer crops of Iran. Quality of the product is immediately lost after harvest due to physicochemical changes. Thus, use of special pre-processes (especially use of edible coating) to delay their maturity and increase the shelf-life of the product is important.

To decrease weight loss, preserve nutritional value (protects against the breakdown of vitamin C) and texture brittleness (corresponding to the higher acceptability of consumers), greenhouse cucumbers were processed with various edible coatings; control (I), Shiraz gum (II) and Shiraz gum containing 1000 ppm peppermint essential oil (III). Then, physicochemical characteristics (pH, weight loss, vitamin C and hardness) and color parameters (L*, a* and b*) of the samples were assessed at storage days of 1, 8 and 16 at 4 oC.

While the vitamin C and firmness of uncoated greenhouse cucumbers (control) respectively decreased to 4.8 and 2.26 times during 16 days of storage, the highlighted parameters decreased at rates of ~3.85 and ~1.20 times in samples treated with coating (III) at similar conditions, respectively. Moreover, strong positive correlations between vitamin C and firmness factors (r = +0.9654 and R2 = 0.932) included significant effects on the perception of consumer mouth feels.

Regarding that the control sample achieved only 57.5% of the maximum organoleptic score (flavor, aroma, color and texture), greenhouse samples treated with coating (III) achieved up to 94% of these characteristics and have been recommended as the best edible coating for the shelf-life extending of greenhouse cucumbers.

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.

The aims of this study were to investigate effects of balangu seed gum on physicochemical and sensory characteristics of low-fat fresh yogurt and monitor these characteristics during the storage.

In this study, effects of balangu seed gum quantity (0–0.1%) and fat content (0 to 2%) on physiochemical and sensory characteristics of the fresh low-fat yoghurt were studied. The low-fat yoghurt was stored for 14 days and then investigated on Days 1, 7 and 14 for physiochemical and sensory characteristics.

Results showed that increases in balangu gum content decreased syneresis and pH of the samples significantly (p< 0.01). Increase in fat content led to a decreases in syneresis and increases in viscosity of the samples (p< 0.01). Furthermore, results showed that increases in balango gum content increased the taste, texture, color and overall acceptance scores (p< 0.01) while fat did not include significant effects on sensory characteristics of the samples. Based on the results, the optimum point for low-fat yoghurt production with minimum syneresis, maximum viscosity and highest taste, texture, color and total acceptance includes balangu gum content of 0.1% and fat content of 1.25%. This product includes viscosity of 1169.49 (Pascal second), syneresis of 36.75, taste score of 4.91, texture score of 4.90, color score of 4.96, total acceptance score of 4.99 and desirability index of 90.1%. Results of physiochemical characteristics after 14 days showed increases in syneresis and viscosity and decreases in pH level (p < 0.01). Sensory specifications did not significantly vary between Days 1 and 7; however, differences were significant on Day 14, compared to Day 1 (p<0.01). Despite these differences, samples included acceptable scores and were appropriate for consumption.

Results of this study have shown that balangu seed gum can be used as an appropriate alternative of fats in fresh low-fat yogurts. Moreover, these yogurts can be stored for up to 14 days.

By increasing consumer demands for food products with no chemical preservatives, use of natural preservatives such as herbs with antioxidant and antimicrobial characteristics as well as effects on physicochemical and sensory characteristics of the products is increasing in food industries. Therefore, the objective of this study was to investigate effects of Echinophora platyloba on microbial, physicochemical and sensory characteristics of pickled cucumbers.

In this study, effects of Echinophora platyloba powder at 1, 2 and 3% on physicochemical (pH, titrable acidity, salt, color and texture), sensory (odor, smell, texture, taste and appearance) and microbial characteristics of pickled cucumbers were assessed during 14 days of storage at ambient temperature.

Results showed that with increasing the proportion of plant powder, pH and firmness of the cucumber samples increased and salt and acidity decreased (p ≤ 0.05). Based on the results of sensory assessment, samples containing 2% of Echinophora platyloba powder were more acceptable than other samples. As the proportion of powder increased, color values ​​of L* and b* decreased but the color value of a* increased. Microbial assessment results showed a significant antimicrobial activity of Echinophora platyloba powder; hence, no fungal and bacterial growths were seen in samples containing 3% of the powder.

In conclusion, Echinophora platyloba can be used as a natural preservative and a substitute for potassium sorbate in preservation of pickled cucumbers.

Use of natural coatings with various capabilities provides the opportunity to produce healthier and more acceptable materials, especially for higher value-added products such as dates. The objective of this study was to investigate effects of date coatings on the fruit various characteristics for the purpose of a longer shelf-life.

Mazafati dates were coated with natural polymers (zein, chitosan and pimpernel essential oil). Effects of coating on various characteristics of dates, including moisture content, total soluble solids, acidity, sugar content, pH and sensory characteristics (color, taste, firmness and brightness), were assessed at 4 and -18 oC for the first year and at 10 oC for the second year. Data were analyzed using factorial experiment in a completely randomized design. Comparisons of the means were carried out using Duncan method.

In organoleptic characteristics, the highest color score belonged to the fruits with chitosan after three months of storage and the lowest color score belonged to chitosan and oil and to control and oil treatments after 12 and 9 months of storage, respectively. Zein and chitosan treatments included better tastes and textures, compared to those other treatments did. In chemical assessments, zein treatments include the highest and chitosan treatments included the lowest moisture contents. The lowest sugar contents were reported in control. No significant differences were seen in acidity and pH contents of the treatments.

Based on the results of sensory and physicochemical assessments, use of the highlighted coating treatments to preserve physicochemical characteristics of the fruit dates as well as chitosan coating to minimize color and zein coating to minimize flavor changes in dates are recommended.

Whey powder is a product of water drying process separated from the curd during cheese making processes. Furthermore, whey is an organic waste of cheese production, including significant uses in food industries, particularly in dairy and fermentation stages because of its special characteristics and high quantities of lactose.

In the present study, two spray drying parameters including dry matter contents of whey (30, 40 and 50% T.S.) and dryer temperatures (150, 200 and 250 °C) were optimized using response surface methodology and then physicochemical characteristics of the powder were assessed as responses.

Results showed that by increasing dry matter contents of input feed solutions, whey powder density and production yield increased but changes in moisture contents were not significant (p > 0.05). As the whey concentration increased (up to 40% T.S.), the powder solubility was enhanced and then decreased. As the dryer inlet temperature increased, the production yield and solubility of the powder increased and the powder moisture content and bulk density decreased. The optimum conditions for whey powder production to achieve the highest production yield and solubility and the lowest moisture content and bulk density of the powder were reported as 39.37% dry matter content of whey and 250 °C dryer inlet temperature.

Based on the characteristics of whey powder, it can be used as a raw material in various fermentation processes and cultures. Moreover, environmental pollutions by dairy plants decrease by production of whey powder.

Most nutrition studies today suggest that there is a direct relationship between nutrition and the health of people in the community. This has led to increasing production and more consumers' desire for beneficial products. The aim of the present study was to produce functional yogurt using grain powder of Salvia Macrosiphon Boiss.

In the present study, the effect of adding grain powder of Salvia macrosiphon Boiss. On some physicochemical properties including titratable acidity, hydration, antioxidant properties, dry matter content, fat and sensory properties of yogurt during 14 days of storage at 4°C was investigated. Analysis of variance was used to test the hypotheses and Duncan post hoc test was used to examine the differences between the treatments.

The addition of seed powder, In addition to increasing antioxidant activity, Caused tissue improved and syneresis reduced and also the shelf life of yogurt increased. With increasing percentage of grain powder, acidity and syneresis decreased and pH, dry matter, fat content and percentage of free radical inhibition increased significantly (p value < 0.05). Also, in terms of sensory characteristics, the highest score in terms of total acceptance related to yogurt sample contained 1% grain powder.

Recognizing nutritional plants and using them in the production of functional products can be a big step in increasing the health of people in the community.

Apple is one of the most valuable high quality products in the world that plays a specific role in the household food basket. Measurement of physicochemical and mechanical properties of fruits is necessary to reduce their wastes, increase quality, and reduce the products final cost in the transportation and handling, storage and processing industries.

In this study, some physicochemical parameters of three varieties of Iranian native apples (Golab, Shafiabadi, and Arous Meshkinshar) such as moisture, color, firmness, total soluble solids (TSS), acidity (based on malic acid), pectin, and pH were measured according to the standard methods.

The results showed that Golab variety has more pectin content, less sugar, more brix, lower pH, and higher firmness, while the Arous Meshkinshahr had low pectin, high sugar content, low moisture content, with lower firmness and brix. All three apple varieties had almost equal quantities of ascorbic acid (vitamin C) and little nitrogen. Shafiabadi variety was high in acidity. In point of color index, there was more greenness for Golab and redness concerned other two varieties.

In terms of measured physicochemical properties in this study, Golab variety due to also high percentage of pectin content might be used in industries such as canning, jam making; and having higher nitrogen content might be used in vinegar production. Shafiabadi variety due to higher soluble solid content and total sugar might be employed for production of dried apple and apple flakes.