Food Technology
Rezvan Shaddel; Shadi Rajabi Moghaddam
Abstract
Introduction
Caffeine is one of the most common bioactive compounds in the world that can enhance mental and physical performance However its bitter taste has created challenges for the use of this compound in food. Nano-encapsulation technology, such as the use of liposomes, is one of the simplest ...
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Introduction
Caffeine is one of the most common bioactive compounds in the world that can enhance mental and physical performance However its bitter taste has created challenges for the use of this compound in food. Nano-encapsulation technology, such as the use of liposomes, is one of the simplest ways to overcome this issue. In this research, caffeine was encapsulated in nanoliposomes coated with chitosan and then the drink powder enriched with caffeine nanochitosome was produced.
Materials and methods
In this research, pure caffeine powder was purchased and stored in dry environment at room temperature. Ethanol (96%) and acetic acid were obtained from Mojallali Company, Tween 80 from Merck Company (Germany), lecithin (P3556), cholesterol (C8667), and chitosan (medium molecular weight) purchased from Sigma Aldrich Company (Germany). Sugar, essential oil and citric acid used in the formulation of the drink were purchased from a local store.
First, nanochitosomes in ratios of 9:1, 8:2 and 7:3 lecithin-cholesterol, were prepared using thin-layer hydration method. Then, the particle size and zeta potential were measured to determine the characteristics of the produced particles. Encapsulation efficiency was measured for 9:1, 8:2 and 7:3 lecithin-cholesterol ratios. The stability of the chitosomal sample with a ratio of 9:1 lecithin-cholesterol was evaluated through visual observation of precipitation formation and the amount of release of encapsulated caffeine during 60 days of storage at ambient temperature was calculated. FTIR was performed for each of the components of the wall of chitosomes, caffeine powder, chitosomal solution containing caffeine and chitosomal solution without caffeine with a ratio of 9:1 lecithin-cholesterol. Nanochitosomes with 9:1 lecithin-cholesterol ratio were used in the formulation of beverages due to having the smallest particle size, favorable zeta potential, the highest microencapsulation efficiency, and high stability during storage. The drink samples were prepared in different formulations (samples containing 3 and 5% free caffeine solution, samples containing 3 and 5% chitosomal caffeine solution and the control sample). Then, the drinks were evaluated in terms of sensory characteristics and other physico-chemical characteristics (pH, acidity, Brix degree, etc.). The drinks produced were turned into powder with a freeze-dryer machine, and two important characteristics of powdered products, i.e. water solubility index and their hygroscopicity, were evaluated.
Results and Discussion
The average particle size and zeta potential for different ratios of lecithin -cholesterol were obtained in the range of 133.3-443.6 nm and +40.96 to +48.36, respectively. The encapsulation efficiency for 9:1, 8:2 and 7:3 lecithin-cholesterol ratios were 91.2%, 86.18% and 79.09 %, respectively. The chitosomal sample with 9:1 lecithin-cholesterol ratio showed good stability during 60 days of storage at ambient temperature. FTIR results showed that caffeine was loaded in nanochitosomes. The results of the sensory evaluation of the prepared beverages showed the acceptability of the taste of the samples containing caffeine nanochitosome compared to the samples containing free caffeine, which indicates the success of chitosomal nanocarriers in covering the bitter taste of caffeine. The results of measuring the color of different drink samples showed that there is no significant difference between the color of samples. The results of measuring pH and acidity did not show significant differences between different drink samples. The results of measuring the solubility of different drink powder samples showed that the samples containing caffeine nanochitosomes have low solubility compared to other drink powder samples. Also, the hygroscopic amount of the drink powder containing caffeine nanochitosomes was lower than the other samples, which is considered as an advantage for powdered products.
The results obtained in this research showed that nanochitosomes are an efficient system in covering the bitter taste of caffeine. Therefore, with the production of caffeine nanochitosomes and its usage in the formulation of powder drinks, it is possible to produce energizing and desirable drinks without the need to use high amounts of sucrose.
Somayeh Rastegar; Azam Shojaee; Behjat Tajeddin
Abstract
Introduction: Persian walnut (Juglans regia) from Juglandaceae family is one of the most important fruits in the world that has an important role in human health. It contains a notable list of plant nutrients that has been found to have disease preventing and health promoting properties. Walnut is a ...
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Introduction: Persian walnut (Juglans regia) from Juglandaceae family is one of the most important fruits in the world that has an important role in human health. It contains a notable list of plant nutrients that has been found to have disease preventing and health promoting properties. Walnut is a source of bioactive compounds such as phenolic and flavonoid complexes where they act as antioxidants and free radical scavengers. It also contains pleasant flavor and high concentration of minerals and fatty acids. Extending shelf-life of this perishable fruit has been accomplished due to its high oil level and oxidation of oil (Tajeddin, 2004). Rate of loss in walnut kernel quality and quantity between harvest and consumption affects its productivity. Control of temperature is the most effective tool for extending the shelf life of fresh horticultural products. However, to reduce high losses and keeping product’s quality, packaging method is very important as well as low temperature. Therefore, in this study, the effect of temperature (4 and 25 oC) and packaging methods (vacuum and air packaging) on the changes of walnut kernel compounds was evaluated to improve quality of its storability during six month cold storage.
Materials and methods: Walnut harvested from a commercial garden at the mountain regional of Raber, Kerman province. All chemical materials for different tests obtained from Merck Company, Germany. Immediately after walnuts harvesting, they were dehulled and dried in expose of sun shade with the circulation of natural air. The walnuts were then transferred to the laboratory and their wooden shells were removed. Subsequently, about 25 g of walnut kernel was packaged in the polyethylene films with 87μm (0.087 mm) thickness, under a vacuum machine and stored at 4°C and 25°C to be later assessed for further analyses intended for six months. Phenol, flavonoid, carbohydrate, protein, water percent, color parameters (C, h, WI), organoleptic characteristics, and peroxide value of kernels were measured every month during storage time. The control samples of packaged walnuts under environmental conditions were also stored. The current study carried out as a factorial assay on the basis of a completely randomized design with three replications at Hormozgan University. Data were subjected to ANOVA using SAS software version 9.4. Verification of significant differences was done using Duncan's Test at 1% probability level.
Results and discussion: Results showed that carbohydrate and proteins decreased during storage time. Both of vacuum package and low temperature contorted the reduction of different characteristics of kernel such as bioactive compounds during storage significantly. Sensory properties were also reduced during storage, especially at the end of period, in all conditions except for treatment at 4°C and vacuum packing. Control samples (temperature 25°C and air-containing packags) during the experiment showed a lower quality for all factors. Samples that stored in low temperature and vacuum package had better brightness (higher chroma, Hugh, lightness (L) and white index values (Wi)) than other treatments. The treatments had a significant role in the preventing of increasing peroxide value. The peroxide value in treated samples was increased from 0.023 to 0.68 meq/g, while in vacuum packages it was changed from 0.023 to 0.37 meq/g. Increasing of peroxide value was observed from 0.023 to 0.68 and from 0.023 to 0.25 meq/g in room temperature and cold temperature, respectively. After six months, the average peroxide value in all samples was less than one milliequivalent per oil kilogram. Decreasing of phenolic compounds (30%) and flavonoids (35%) and increasing the peroxide index simultaneously led to the reduction of the appearance and organoleptic properties of the control samples. Generally, vacuum package and low temperature condition that using in this study showed the best effect on the nutritional compounds quality of walnut kernel such as bioactive components during six months storage. Shelf life enhancement of walnut by vacuum packaging in the different polymers has been already reported by Tajeddin, 2004.
Rohollah Pashaei Bahram; Sodeif Azadmard Damirchi; Javad Hesari; Seyed Hadi Peighambardoust; Samad Bodbodak; , Boukaga Farmani
Abstract
Introduction: Cornelian cherry is one of horticultural crops in Iran. There are about 1094.26 hectares of cornelian cherry orchards in Iran and 2329.36 ton cornelian cherry fruit are produced annually based on statistics of the Ministry of Agriculture-Jahad. Cornelian cherry fruit is usually consumed ...
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Introduction: Cornelian cherry is one of horticultural crops in Iran. There are about 1094.26 hectares of cornelian cherry orchards in Iran and 2329.36 ton cornelian cherry fruit are produced annually based on statistics of the Ministry of Agriculture-Jahad. Cornelian cherry fruit is usually consumed in fresh form, but it products are also used in form of dried fruit, jam, pickles, sauce, juice, jelly, marmalade, vinegar, fruit roll-ups (Golriz et al., 1996; Demir and Kalynoco, 2003; Gulcin et al., 2005) and syrup (Damir et al, 2003; Jayaprakasam et al., 2006). Cornelian cherry fruit is a rich source of antioxidant compounds and has different benefits such as nutritional, medicinal value, profitability and export values (Panatelidis et al., 2006).Total anthocyanins content of most varieties of Cornus are 15-10 times higher than other fruits more that are used as anthocyanins source (Vareed et al., 2007). Although it is obvious that bioactive compounds of cornelian cherry fruit are valuable, but there is little information about changes of their composition and activity during postharvest storage. Some parameters such as Storage temperature, light and exposure to oxygen have great influence on the stability of the composition during postharvest storage of the fruits (Kalt et al., 1999). Since cornelian cherry is a climacteric fruit, the aim of the research was studying the effect of storage and transport of cornelian cheery in ambient temperature on physicochemical properties and bioactive compounds. Two ways of cornelian cherry preservation are included storage of cornelian cherry at room temperature and storage in dried form.
Materials and methods: Cornelian cherry fruit is supplied from an orchard in the city Horand in east Azerbaijan Province from a high yielding tree. After picking, fruits were sorted and held in incubator (25 ˚C) for 9 days and were sampled at intervals of 24 hours up to 9 days and physico-chemical parameters of samples such as pH, acidity, dry matter, Total ash and loss of their bioactive compounds (total phenols, total flavonoids, total anthocyanin, vitamin C and antioxidant capacity) were evaluated. In this research, the effects of storage time on the physicochemical properties and bioactive compounds contents of cornelian cherry fruit during storage at room temperature (25 ˚C) were analyzed by means repeated measurements in time method in three replications. The results obtained were analyzed by using analysis of variance and mean comparison using the least squares (p≤0.05).
Results and discussion: The results showed that pH and acidity significantly increased and decreased during storage time respectively. It could be attributed to consumption of organic acids in the respiration pathways as a substrate and use of them by mold. It gradually led to an increase of pH and improved the condition for yeast growth. The results showed that after 9 days storage at 25 ˚C the amount of Vitamin C decreased from 1385 to 354 (mg/100 gd. b). It could be ascribed to oxidation of Vitamin C during storage in presence of air. Total anthocyanins decreased from 379 to 195 (mg/100 gd. b) which is the result of degradation of the compounds in presence of oxygen and condensation of them with tannin and protein compounds during storage at ambient condition) PiljacZegarac et al., 2011). The amount of total phenols increased from 1237 to 2067 (mg/100 gd. b) During 9 days of storage at ambient conditions. The increase of phenolics compounds could attributed to release of them from protein and carbohydrate complexes (Doshi & Adsule, 2008). Prior et al. (2005) concluded that increase of phenolic compounds during storage of fruits could be the result of moisture decrease and reducing sugar content increase and their interaction with folin ciocalteu reagent. Also flavonoid content of cornelian cherries increased from 491 to 943 (mg/100 gd. b) During storage which probably is due to release of flavonoid compound during ripening process in postharvest storage time. Also, the antioxidant activity was reduced to 33%. According to the results, it could be concluded that storage of cornelian cheery fruit in ambient condition significantly decreased the bioactive compounds. Therefore it was recommended that cornelian cheery should be stored in low temperature condition and consumed in fresh form in short time after harvesting in order to remain nutritional properties and bioactive compounds.
Maryam Farahmand; Mohammad Taghi Golmakani; Asgar Farahnaki; Gholam Reza Mesbahi
Abstract
Introduction: The pomegranate (Punica granatum L.) belongs to the family Punicaceae, which is planted around the world in different microclimatic areas. The pomegranate production has grown uninterruptedly, which is presumably due to the increasing consumer awareness of the benefits attributed to pomegranate ...
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Introduction: The pomegranate (Punica granatum L.) belongs to the family Punicaceae, which is planted around the world in different microclimatic areas. The pomegranate production has grown uninterruptedly, which is presumably due to the increasing consumer awareness of the benefits attributed to pomegranate and its polyphenols. Pomegranate fruit has valuable compounds with functional and medicinal effects like antioxidant, anticancer, and anti-atherosclerotic effects. Storage of juice concentrate can have a dramatic impact on physicochemical quality. The bioactive compounds and antioxidant activity in fruit juice products are influenced by many external factors like different storage temperatures. Knowledge of the rheological behaviour of juice products is essential for product development, design and evaluation of process equipment like pumps and piping. Pomegranate concentrate is so susceptible to the condition of storage, which results in a reduction in consumer acceptability and quality losses. Accordingly, the industrial concentrate stores frozen (-20 °C) which has a lot of costs to the producer. The objectives of this study were to evaluate the degradation visual color, the rheological characteristics of pomegranate juice concentrates, the stability of phytochemicals, the antioxidant activity, and the haze formation of reconstituted pomegranate juice concentrate during storage at different temperatures to determine the best storage conditions to reduce the quality losses and solving the problem about high cost of storage.
Materials and methods: The concentrated pomegranate (Punica granatum (L.) cv. Rabab) juice used in this study supplied from Narni (Green farm, Neyriz, Iran) factory. The pomegranate juice concentrate was poured into falcons for measuring physicochemical attributes, and micro tubes for determination of antioxidant activities. Then the samples were divided into four parts and stored equally in four different temperatures (-20, 4, 20, and 35 °C). The control samples were stored at -80 °C as fresh sample for the storage period (140 days). Folin-Ciocalteu reagent and 2,2-diphenyl-1-picrylhydrazyl radical (DPPHº) were supplied from Sigma-Aldrich Company (St. Louis, MO, USA). All other chemicals were of analytical grade and purchased from Merck Company (Darmstadt, Germany). The total soluble solid (TSS) was determined with a digital refractometer (Carl Zeiss, Germany). Total insoluble solid was measured by centrifugation at (5,000 × g) according to the IFFJP method 60, using a high speed centrifuge (Ibarz et al., 2011). The haze formation of reconstituted juice was determined by “settling” in a glass tube for 3 hour at room temperature. Color measurements of the juice samples were carried out using a HunterLab (CHROMA METER CR-400/410, KONICA MINOLTA, Japan) after dilution. The rheological characteristics of the pomegranate juice concentrate stored in different temperatures were studied by using a computer controlled rotational viscometer. Sample compartment was monitored at a constant temperature (25°C) using a water bath/circulator, while TSS was 65 °Brix. The viscosity measurements, was carried out According to the methods described by Cárdenas et al., (1997), using a Brookfield cone and plate viscometer (DVII pro Brook field, USA) between the shear rate of 0.5–200 (1/s). Total phenolic content of samples was measured according to the Folin-Ciocalteu colorimetric method (Sun et al., 2007). Total flavonoid content in juices was determined via a spectrophotometer according to the method of Chang et al. (2002). Radical scavenging activities of the samples were measured by using DPPHº as described by Mazidi et al., (2012). The ferrous ion reducing antioxidant power (FRAP) of the samples was measured calorimetrically according to the method by Fawole and Opara (2013). All analyses were performed by the Statistical Analysis System (SAS) software V 9.1 (SAS Institute, Inc., Cary, NC, USA). By using the analysis of variance (ANOVA), the differences among means were determined for significance at P< 0.05.
Results and discussion: The industrial pomegranate juice concentrate stored at (-20, 4, 20, and 35 °C) for 20 weeks, and some physicochemical properties like the second turbidity, CIE Lab color parameters, the rheological properties, the bioactive component (total phenolic and flavonoid contents), and antioxidant properties (FRAP and DPPH) investigated in order to determine the best condition of storage. The second turbidity was obvious among the samples stored at 35 °C in the last fourth weeks. Although there were no significant differences among L* value of the samples stored at -20, 4, and 20 °C, a* and b* value of the samples stored at -20 and 4 °C had the same reduction trend for 14 weeks. Even though the control samples had shear thinning behavior, the samples showed a dilatant behaviour after storage. Antioxidant activities measured via DPPH and FRAP sowed reduction with increasing time and temperature. Flavonoid content increased by increasing time and temperature. In conclusion, storage at 4 °C for 14 weeks was the best storage condition to keep the quality and reduce the costs.
