جستجوی مقالات مرتبط با کلیدواژه "concentration" در نشریات گروه "صنایع غذایی"

Rose hip (Rosa canina L.), as a valuable medicinal herbs of Iran, has beneficial effects on the human health. High dose of the rosehip should be used to be effective on the health and anti-inflammatory activity, but it is difficult especially due to its flavor and texture. Therefore, the main goal of the research was to produce rosehip concentrate to increase the bioactive components in the extract and promote the health. Therefore, the effect of ethanol concentration (20-96%), solvent/solid (S/S) ratio (5:1- 15:1 ml/g) and the extraction time (6-24 h) on the components of the extracted samples of rosehip was investigated to select the treatment with the highest bioactive components. The results indicated that increasing of the S/S ratio enhanced all of the components; although the extraction time hadn’t any significant effects on the extraction yield. Increasing the ethanol concentration enhanced total flavonoid content (TFC) and total carotenoid (TC) and decreased total phenol content (TPC). Therefore, to obtain the highest TC and TFC (at optimum condition including S/S ratio 14.94 ml/g, time of 6 h and 96 % ethanol) and highest TPC (at optimum condition including S/S ratio 15 ml/g, time of 6 h and 35.8 % ethanol) , two stages extraction was selected. Finally, these two obtained extract were combined and concentrated under vaccum condition at 45 °C and then, freeze dried. The highest total triterpenoid content (8 % triterpenoid per weight of extract powder) was related to the two staged extract.

Hyssopus officinalis is a belongs to Lamiaceae family and a herb widely growing in Iran .The aim of this experimental study was to evaluate the antimicrobial effect of Hyssopus officinalis extract in 4 ways: disc diffusion agar, well diffusion agar, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) on some microorganism pathogen “in vitro”. The results showed that with increasing the concentration of Hyssopus officinalis extract, the inhibition zone diameter increased. The highest inhibition zone with a diameter of 19.70 mm was observed at a concentration of 80 mg/ml for Gram-positive bacteria Staphylococcus aureus. At a concentration of 80 mg/ml, the ethanolic extract of Hyssopus officinalis showed the lowest inhibition zone observed with a diameter of 13.30 for Escherichia coli. The results showed that the MIC of Hyssopus officinalis extract for Pseudomonas aeruginosa, Escherichia coli Staphylococcus aureus and Listeria innocua was 64, 64, 8 and 16mg/ml respectively. The MBC for 128, 128, 32 and 64 mg/ml respectively. The data obtained in this study confirmed that Hyssopus officinalis extract inhibit growth some microorganism pathogen “in vitro”.

The berry tree is native to the dry climates such as Iran. Its fruit is juicy and rich in sugars, minerals and vitamins. Condensed mulberry extract has a lot of applications in various food industries as sweetener. The purpose of this study was to introduce a suitable method for production of high quality mulberry extract in order to prevent the loss of mulberries at the time of production peak and use the unique properties of berry fruit outside of the production season. In this project, three concentrating methods such as sunny, under conventional conditions and vacuum concentration were used to produce samples with desired brix of 65. Samples were packed in plastic pet bottles and kept in a lab environment away from sunlight for 3 months. Physicochemical experiments including pH, acidity, consistency, color, transparency and sensory properties such as flavor, aroma, concentration and total acceptance of samples were performed in two stages of 3 months and the results compared with each other. The results showed that the color factors L a b were more suitable in traditional samples. These factors decreased over time. The highest pH belonged to the industrial sample (4.84) and the lowest pH belonged to the sunny sample (4.61), and the pH of the samples decreased over time. The transparency of sunny sample (1.57) and industrial (0.804) were the highest and the lowest, respectively and transparency increased over time. In terms of sensory properties, the taste and aroma of traditional sample with scores (3) and (2.916) and the concentration of sunny sample with score (3.416) were the best samples. In conclusion, the traditional sample was selected, and the sunny sample was ranked second.

The aim of this work was to assess rheological behavior of sour pomegranate juice concentrates Pomegranate juice was concentrated by heating at two pressure levels, atmospheric at 90-950C and vacuum (0.1 atm) at 750C, in three soluble solid concentrations 15%, 25% and 45%. The effect of these operating parameters on pH, acidity, density, color and rheological behavior (storage modulus and loss modulus) of pomegranate juice concentrate versus time of concentration was evaluated. The results showed that by increasing heating pH decreased and acidity of samples increased. There was a linear correlation between density and concentration degree of samples (R2 = 0.92). Also, viscosity of samples is dependent on operational pressure and concentration degree (p-value

Raspberry is a good source in terms of antocianines, polyphenols, vitamin C, fibers, proteins and minerals contents. Raspberry juice is susceptible to enzymatic and microbial reactions, because of its high moisture content (75-90%). Concentration of Raspberry juice increases its shelf life, while decreasing costs of storage and transport. In this study, extracts obtained from two raspberry cultivars of Amol (red) and Siyahkal (black) were concentrated by two methods, radiation (microwave) and convention (evaporator-rotary) applying three pressure levels: 12, 38.5 and 100 kPa. Changes in physicochemical properties including brix, acidity, pH, turbidity and color were assessed during the concentration process of two kinds of juice. Results showed decrease in acidity and color and increase in brix and turbidity of the juices, but rate and amount of changes were dissimilar in different methods and pressures. Samples concentrated by radiation using microwave in comparison with conventional method (evaporator-rotary) had superior quality. Furthermore, decrease in pressure led to better quality in product in both techniques.

Liquorice (Glycyrrhiza glabra) of the family Leguminosae is a 30±60 cm tall shrub having blue or violet flowers. Its roots are 15±20 cm long and have a cylindrical rod shape of 0.5±2.5 cm in diameter. Liquorice root contains a variety of compounds, the most prominent of which is the water soluble triterpenoid glycoside glycyrrhizin that constitutes about 16 %. It is responsible for the characteristic sweet taste of liquorice (50 times sweeter than sucrose). The root also contains various sugars (to 18%), flavonoids, saponoids, sterols, starches, amino acids, gums, and essential oil. The water extract of liquorice root has found wide uses in medicine, pharmacology and food industry because of its physical and functional properties.
In the food industry, its distinctive flavour makes it a popular sweetening/flavouring agent. It is also used as an emulsifier to create foam in drinks and beverages. Liquorice root extract is commonly consumed and marketed in liquid, concentrated, dry and powdered forms.
Knowledge of the flow (rheological) behavior of the concentrates is useful in quality control, sensory evaluation and engineering applications that are related to the proper design and operation of unit operations, as well as for the understanding of the pertinent transport processes in the operations.
The purpose of this investigation was to characterize the rheological behavior of liquorice extract concentrates and study the effect of temperature and soluble solids on the viscosity.
Extraction was made at 50°C and water to liquorice root mass ratio of 4:1. The mixture was shaken continuously for 100 min, centrifuged for 10 min and then filtered to obtain a clarified extract, which was concentrated to 50°Brix in a laboratory rotary vacuum evaporator.
The rheological behavior of licorice extract has been studied at temperature range 10-70 0C and 5-50 % soluble solids using Brookfield viscometer.
The obtained results showed that all the samples exhibited Newtonian behavior at all the studied temperatures and concentrations. The flow index decreased slightly with sample concentration. Several workers observed Newtonian behavior of clarified and depectinated juices.
The shear stress versus shear rate data obtained were well fitted to Newton's model. An increase in temperature decreased the viscosity and this inverse relationship has been likened to the incidence of a freer molecule to molecule interaction at elevated temperatures. Since viscosity is an indication of the resistance to flow such a freer interaction is expected to minimize the resistance.
It was observed that, irrespective of the temperature a decrease in soluble solids content decreased the viscosity. It is due to dilution which increases the separation between the particles, thus decreases interaction between the particles.
In contrast, the opposite effect was observed when soluble solids content became higher. Arrhenius type equation was found to be suitable in describing the relationship with correlation coefficient values between 0.94 and 0.99. The activation energy increased with the soluble solids content; therefore, temperature had a greater effect on samples with higher soluble solids content. The data obtained in this study can be used in designing equipment for handling of concentrated liquorice root extract at the temperature range studied.

Iran is one of the largest pistachio producer and exporter in the world. Under unfavorable conditions during storage, pistachio quality will be reduced due to undesirable reactions. This study was conducted to evaluate the influence of chitosan coating with different molecular weights and concentrations on oxidation activity in the Akbary variety of pistachio nuts. Therefore, using acetic acid as 1% (v/v), chitosan with low molecular weight (LMC) and medium molecular weights (MMC) at concentrations of 0.5%, 1% and 1.5% V/W were prepared and pistachios were coated by them. In order to prepare control group, coating was performed with water and acetic acid as 1% V/V. Coated pistachios were packed in polyethylene bags and kept at room temperature and relative humidity (25-27 °C and 35-45%) for six months. Samples were examined every two weeks for peroxide and thiobarbituric acid value during storage. The results showed that during storage, chitosan coating reduced the rate of oxidation significantly (P <0.05). The LMC exhibited higher anti- oxidant activity than MMC and increased concentration correlated with higher antioxidant activity. The thiobarbituric acid value of pistachios was always zero due to non-formation of secondary compounds of oxidation reactions. In this research, LMC was found appropriate edible coating material for pistachio nuts.

Production of high volume of sludge is an important problem in wastewater treatment plants that necessitates approach of a proper economical and environmental management method. Chemical conditioning is used for increasing sludge dewater-ability and its volume reduction. Researchers have shown that use of natural compounds have environmental superiority over chemical ones. Therefore، in this research the effect of three food wastes including starch، white bean and pomegranate skin extract on the sludge dewatering capability in lab scale batch system was investigated. From the results، pomegranate skin extract in optimum pH of 4 and concentration of 1000 ppm gave the best efficiency. In this case، the amount of TTF، sludge cake humidity، volume of filtered water in 10 second، sludge volume reduction and turbidity were 10 seconds، 88. 31 percent، 50 ml، 25. 55 percent and 24 FAU، respectively.

In this research the production of tomato juice concentrate in the fruit nectar production plant and using existing equipments have been studied. Tomato juice was produced and then concentrated under high vacuum condition at temperature lower than 50 oc up to 20. 25 Brix in the laboratory scale. In order to study the quality specifications of the tomato concentrate and juice، the concentrated juice was recombined and physical and organoleptical tests including color، appearance، consistency and flavor were performed. The samples kept for one and three months at temperatures 4،25and 35˚C were studied. Results showed that fruit nectar production line has significant effects on color and vitamin C content of tomato juice. However with additional equipments it is possible to produce a high quality tomato juice concentrate. Moreover it was found that the concentration of tomato juice، had no significant effect on the quality of recombined product and 97 % of vitamin C content was remained unchanged.