Food Technology
Ali Kashani; Maryam Hasani; Leila Nateghi; Mohammad javad Asadolahzadeh; Parvin Kashani
Abstract
Introduction: Nowaday, the demand for low calorie food based and keeping primary features including texture and taste is increasing. Jelly is one of low calorie products produced from fruits and other components, and its consumption is increasing for human health. Jelly is semi-solid and transparent ...
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Introduction: Nowaday, the demand for low calorie food based and keeping primary features including texture and taste is increasing. Jelly is one of low calorie products produced from fruits and other components, and its consumption is increasing for human health. Jelly is semi-solid and transparent product that prepared with the use of sugar or juice and pectin or gelatin and flavor and color may also be added. Potato peels contain valuable substances such as pectin. Using potato peels to produce pectin with appropriate properties can solve the environmental issue resulting from these wastes in addition to make value added product. Pectin is a complex polysaccharide that is found in the wall of early plant texture and in the intercellular layer. Pectin contains a group of rich polysaccharides of galacturonic acid units with lower amounts of different sugars (Baiano, 2014). Two commercial forms of pectin are available: high-methoxyl and low-methoxyl pectin (high ester and low ester pectin). High-ester pectin forms a gel in a solutions containing high soluble solids and acidic systems, whereas low-ester pectins form more gel at wider pH and range of solids content but they do require divalent cations to form the gel (Kratchanova et al., 2012). In the food industry, pectin is used as a jelly-making agent, especially in the production of jellies and jams. Pectin is also used in fillers, medicine, pastries, bakery products and also as a stabilizer in juices and beverages, as well as in dietary fiber (Sharma, 2006). Pectin also has therapeutic benefits such as lowering blood cholesterol levels, removing heavy metal ions from the body, stabilizing blood pressure and facilitating intestinal activity (Ptichkina et al., 2008). Temperature, pH, and acid extraction time are the most important factors affecting the extraction yield and quality of produced pectin (Yapo et al., 2007). Currently, almost all commercial pectins are produced from citrus or apple peels, both of which are juices by-products (Thirugnanasambandham et al., 2014). Therefore, the main objective of this study was to optimize the conditions of extraction of pectin from potato peel by response surface methodology and to compare the physicochemical properties of Jelly produced from potato peel under optimum conditions with Jelly produced from apple and citrus Material and methods: Potato of Granola variety was purchased from the local market in Ardebil. The chemicals used for the tests include: citric acid, sodium hydroxide, phenolphthalein, and Calcium chloride were purchased from Merck Company (Germany). The method of Hoseeni et al (2017) was used for jelly production with slight modification as follows. In the First step,0.5 and 1% pectin extracted from potato peelings, 30 % Sugar, 0.014 % Cherry edible color and 0.75 % Cherry essential oil were mixed then 100 CC Boiling water was added to the mixture and mixed again. After the sugar was completely dissolved, 15, 30, and 45 mg of calcium chloride was added per gram of pectin. The pH of the samples was regulated by citric acid solution on 2.5 and 4. The heating of the samples was continued until the brix of the treated treatments was set to 42. The prepared samples were kept at room temperature for half an hour. The treatments were then refrigerated for 2 to 3 hours to complete the jelly closing process. For this purpose some jelly characteristics such as texture properties, physico-chemical (pH, acidity, brix, moisture and Drainage) and sensory properties of samples were investigated using five point hedonic scale. A one-way analysis of variance and Duncan test (P≤ 0.05) in three replications were used to establish the significance of differences in the experimental data. The results were analyzed using the Minitab version 16. Results & Discussion: Results showed that by increasing calcium chloride, pH and Pectin concentration had a significant effect on increasing the hardness of the gel and the strength needed to make the gel brittle (P≤0.05).The highest hardness of the gel in pectin emulsion extracted from potato peel was 30.0959 N and highest force required to break the gel was 27.3431 N in the most severe extraction conditions at Calcium chloride 35.2286 mg/g, Pectin concentration 1% and pH 4. Results of physico-chemical properties showed that there was no significant difference between pH, acidity, brix and moisture of jelly made from apple pectin and citrus and apple commercial pectin. The results of the syneresis showed that the syneresis by the jelly of potato pectin is not similar with jelly from apple pectin and citrus and apple commercial pectin significantly different. Also Results of sensory properties showed that it was no significant difference between jelly from apple pectin and citrus and apple commercial pectin. The results of this study showed that by optimizing the production conditions, potato pectin can be used in jelly formulation and jelly can be produced with desirable and comparable quality compared to the commercial pectins
Sara Karamzadeh; Sara Ansari
Abstract
Introduction: Pectin is a complex mixture of polysaccharides in the primary cell wall of plants which is a polymer of α-galacturonic acid, to which neutral sugar is connected to form aside chain. Pectin is a natural food additive used extensively in the food industry as thickener, texturizer, emulsifier, ...
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Introduction: Pectin is a complex mixture of polysaccharides in the primary cell wall of plants which is a polymer of α-galacturonic acid, to which neutral sugar is connected to form aside chain. Pectin is a natural food additive used extensively in the food industry as thickener, texturizer, emulsifier, stabilizer and gelling agent. In 2018, the world market demand for pectin was in excess of 60,000 tons and Europe was estimated to have the largest market with 31,000 tons (valued about US$420). In Iran, about one hundred tons of pectin is consumed annually in the food and pharmaceutical industries, all of which are supplied from abroad, and due to its price in the world market is of considerable magnitude. Therefore, the study of its production within the country could be of great importance. During processing and canning of eggplant, its cap and skin are discarded as waste which can be considered as a valuable ingredient in the food industry. The main objective of this study was to develop an MAE (Microwave assisted extraction) of pectin from eggplant peel and investigate the effect of process variables (microwave power, irradiation time and pH) and the response (extraction yield, degree of esterification, galacturonic acid content and emulsifying activity); and to obtain optimum conditions for maximum extraction yield of pectin from eggplant peel. The response surface methodology (RSM) using Box-Behnken design was employed in this study. Material and methods: Eggplant peels were provided by Yek-o-Yek factory as an unwanted by-product. Then, the peels were divided into small pieces and dried in hot air oven at 65 °C until it attains constant weight. The peels were then grinded and passed through a 40-mesh sieve to obtain powdered sample. The independent variables examined were microwave power (360–450–540 W), irradiation time (1–2.5–4 min) and solution pH (1–2–3). MAE of pectin was performed in an ordinary household microwave oven with a total of 17 treatments according to RSM. About 5 g of dried eggplant peel powder was weighed and placed into a 250 ml beaker, 75 ml distilled water (the liquid-solid ratio 15:1 v/w) containing different pH values was added and exposed to microwave radiation at different powers for the selected irradiation times. After microwave heating, the mixture in the beaker was allowed to be cooled down and filtered using filter paper (Whatman no-1). The filtered extract was centrifuged and the supernatant was precipitated with an equal volume of 98% (v/v) ethanol. The coagulated pectin mass was washed with 98% (v/v) ethanol for two times and dried in oven at 60 ° C until it attains constant weight. The pectin extraction yield was calculated by dividing the weight of dried pectin to the weight of dried eggplant peel powder. Galactoronic acid content of pectins was determined using the meta-hydroxydiphenyl method. The esterification degree of the pectins was determined by the titrimetric method with minor modifications. The emulsifying activity (EA) of the eggplant peel pectins were analyzed according to the method by Dalev & Simeonova (1995). Optimum extraction conditions to achieve maximum extraction efficiency, degree of esterification, galacturonic acid content and emulsifying activity were determined. Then, the stability of the oil-based emulsion prepared by mixing 0.5% w/w solution of pectin extracted in optimal conditions and corn oil, were examined at 4 and 23 ° C. In addition, the behavior of pectin extracted under optimal conditions (at concentrations of 0.1, 0.2, 1 and 2%) and its spectra using a Fourier transform infrared spectrometer (FTIR) were investigated. Results and discussion: The results indicated that the extraction efficiency, esterification degree, the amount of galacturonic acid, and the emulsifying activity of the pectins extracted were 2.20- 17.16%, 20.20- 36.13%, 51.3- 74.7%, and 1.87- 21.64%, respectively. With increasing microwave power, irradiation time and decrease of solution pH the extraction efficiency of pectin extracted increased, while esterification degree decreased. The amount of galacturonic acid and emulsifying activity showed an upward trend up to microwave power of 450 watts and the irradiation time of 3 minutes after which demonstrated a downward trend. The optimum conditions for reach to the maximum extraction yield, galacturonic acid content and emulsifying activity were in microwave power of 360 W, irradiation time of 4 min and pH of 1 that at these conditions, the extraction yield of 16.17, galacturonic acid content of 70.81 and emulsifying activity of 2.68 were predicted. Also, these observations indicated that with increase in concentration, the flow behavior of pectin solutions was changed from Newtonian to pseudo-plastic. In addition the stability of pectin-stabilized emulsion at 4°C was more than 23°C. In general, this study showed that the microwave method could be used as a novel and high-performance method for extracting pectin from eggplant peel.
Sanaz Ghassemi; Seyed Mahdi Jafari; Morteza Khomeiri; Elham Assadpour
Abstract
Orange peel oil,a widely used industrial flavoring, is volatile and chemically unstable in the presence of air, light, moisture and high temperatures. Biopolymer Nano complexes, a bunch of Nano carriers, are produced between groups of charged polysaccharides and proteins with the use of electrostatic ...
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Orange peel oil,a widely used industrial flavoring, is volatile and chemically unstable in the presence of air, light, moisture and high temperatures. Biopolymer Nano complexes, a bunch of Nano carriers, are produced between groups of charged polysaccharides and proteins with the use of electrostatic interactions. The nanoparticles are able to carry, protect, and increase their bioavailability of food-drug materials. Hence, in this study, the Nano complexes of pectin- whey protein concentrate, as a carrier of orange peel oil, were produced and the features of prepared Nano complex solution with various concentrations of whey protein (4, 6 and 8%), pectin (0.5, 0.75 and 1%) and different values of pH (3, 6 and 9) were studied. The Viscosity, stability and color (index L *) of the treated designs, done in a response surface methodology, were examined. The results showed that whey protein 4% and pectin 1%( with a pH of 3 and 9) had the lowest and highest stability respectively. Also this treatment with a pH of 3 showed the highest viscosity as well as the highest L *. The lowest viscosity was achieved by whey protein 6% and pectin 0.75% with a pH of 3, and because of the unbalanced compound, the complex did not form and a phase separation occurred. The lowest L * was obtained by whey protein 4% and pectin 0.5% with a PH of 9. Ultimately, whey protein 4% and pectin 1% with a PH of 3 were selected as the optimum sample because of formation the strong and suitable complex. Particle size and zeta potential measurement of optimum sample, were 160 nm and -0.53 mV respectively.
Mohammad Farhadi Chitgar; Mehran Alami; Yahya Maghsoudlou; Mohammad Reza Ataroudi
Abstract
Introduction: Gummy candies are included in many confectionery products, such as jellies, pastilles and etc. The texture of gummy candies is achieved by using various gelling agents, such as gelatin, starch and pectin. Color is the most important quality attribute of gummy candies because it is appreciated ...
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Introduction: Gummy candies are included in many confectionery products, such as jellies, pastilles and etc. The texture of gummy candies is achieved by using various gelling agents, such as gelatin, starch and pectin. Color is the most important quality attribute of gummy candies because it is appreciated for its intrinsic aesthetic value and also allows us to estimate food quality. Synthetic dyes have commonly been applied for food coloring purposes because of their stability against light, oxygen and heat. However, some of these synthetics have been related to toxic effects and it has been reported that their consumption affects children's behaviors. Therefore, synthetic dyes are being increasingly replaced by natural pigments. The principal groups of natural food colorants are anthocyanins, betacyanins, carotenoids, curcuminoids, and chlorophylls. Among these pigments, anthocyanins have gained growing interest because they are widely distributed pigments in nature and represent a wide range of color from red and orange to purple and blue. Berberis b .L (barberry) is the largest genus in the family Berberidaceae and contain about 450–500 species of deciduous or evergreen shrubs. Iran is the largest producer of barberry (B.vulgaris) in the world. Besides, other species in different parts of Iran, especially North Khorasan province, grow wildly. B.cratagina is one of the wild barberries which is known as black barberry among Iranian people. B. cratagina contains large amounts of anthocyanin that can be used as an alternative to synthetic colorants. However, its successful application mainly depends on the stabilization of its anthocyanins. Studies have been shown that some hydrocolloids especially pectin can enhance the stability of anthocyanins. So, the aim of this study was to evaluate the effect of different concentrations of high methyl esterified apple pectin on the degradation kinetics of monomeric anthocyanin and visual color parameters (L, a*, b* and TCD) of black barberry in a fruit pastille model system.
Material and Methods: The fruit pastille prepared according to Demars & Zeigler (2001) recipe. Six g gelatin was mixed with pectin (the amount of pectin was varied between 0.5, 1, 1.5 and 2 g) and 20 g water in a beaker. The mixture was heated and deairated in a water bath. Additionally, 30 g of sucrose, 25 g of glucose syrup (80°Brix) and 10 g of water were combined, the mixture was heated at 115°C(2 min), resulting in a total soluble solids content of 80°Brix and added to the gelatin solution. Subsequently, after cooling to 80°C the Berberis juice (10 g ) was added to the mixture Finally, the gel solution was poured into a plastic molds, stored at 4°C for 24h and dried at 25°C until aw=0.6. For shelf life experiments, samples were stored under dark (20±0.5°C) condition for a period of 30days. Samples were drawn at regular intervals of 6 days to quantify total anthocyanin and for color analyses. Total anthocyanin content of samples was determined by the pH differential method and color analysis was performed using computer vision. Linear regression analysis was applied using Slide write software version7.0 to obtain the kinetics parameters. All experiments were repeated at least three times and results were expressed as mean ± SD. Significant differences (α=0.05) of physicochemical properties and kinetic parameters throughout storage were determined using the Duncan's test for differences between independent samples. Data evaluation was performed using the SPSS software version16
Result and Discussion: There was a significant difference (P
Elham Ansarifar; Fakhri Shahidi; Mohebbat Mohebbi; Arash Koocheki; Navid Ramazanian
Abstract
Introduction: Microencapsulation has become an important technique in the food industry. One of the methods of producing microcapsules is to use layer-by-layer adsorption, in which oppositely charged polyelectrolytes are adsorbed consecutively onto a colloidal template. Creating multilayer films based ...
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Introduction: Microencapsulation has become an important technique in the food industry. One of the methods of producing microcapsules is to use layer-by-layer adsorption, in which oppositely charged polyelectrolytes are adsorbed consecutively onto a colloidal template. Creating multilayer films based on electrostatic interactions between oppositely charged components was introduced in 1991 by Decher et al. Layer-by-layer (LbL) polyelectrolyte deposition has become a popular technique for preparing polyelectrolyte capsules because of its ability to create highly tailored capsule shells through a simple, inexpensive and easily controllable adsorption process. It has been applied to produce capsules of various sizes, ranging from the nanometer to micrometer scale, with well-defined barrier properties. In this technique, assembly is driven by the electrostatic attraction of oppositely charged materials to form polyelectrolyte shells. The structure of the polyion layered capsule shell is determined mainly by the electrostatic interactions between the polyions used. The mechanical strength and permeability of the capsules can be controlled by varying the number of layers or by changing the characteristics of the encapsulating materials. The purpose of this study was to produce microcapsules using supramolecular assemblies consisting of common food ingredients such as soy protein isolate (SPI) and high methoxyl (HM) pectin. Moreover, some features of the developed microcapsulation were studied.
Materials and methods: SPI fibrils were prepared based on the method developed by Akkermans et al., (2008) and its morphology was studied using transmission electron microscopy (TEM) and atomic force microscopy (AFM). 0.5% (w/w) SPI fibril and pectin solutions were prepared by mixing at pH 3.5 were left stirring overnight. The LbL process for the production of microcapsules with protein fibril-reinforced nanocomposite shells has been described in Humblet-Hua et al., 2012. It starts with the production of A 2% w/w emulsion of (0.05 gr diacetyl in 1.95gr sun flower oil) in fibril SPI solution is produced using a homogenizer with a rotor-stator dispersion tool using a setting of 13500 rpm for 90 S. Because the proteins are below their isoelectic point, the emulsion droplets have a positive charge. To avoid interactions between the nonadsorbed SPI and the biopolymer of the next layer, the droplets are separated from the serum by means of centrifugation. After the isolation, the droplets are dispersed into a solution of HMP. The HMP is negatively charged at the chosen pH of 3.5. The bilayered droplets can be isolated again and dispersed in a fibril solution to deposit a third layer of a positively charged mixture of SPI fibrils. Subsequently, additional layers of HMP and SPI fibrils can be deposited by repeating the same procedures. Some features of the microcapsulation, including size, zeta potential, and morphology and release kinetics were studied.
Results & discussion: TEM and AFM micrographs showed that SPI fibrils obtained had a contour length of a few hundred nanometers, thickness of between 1 and 10 nm and its structure is highly branched. One of the most common problems reported in previous studies using the LbL technique to produce multilayer particles, is the tendency for flocculation. In the present system, this problem was not observed. The size distribution of isolated emulsion droplets (templates) did not change significantly from 1-layer droplets to 5-layer droplets. In other words, the emulsion droplets were stable against flocculation after applying more layers of polyelectrolytes. The Sauter mean diameters D (3, 2) of these droplets fluctuated between 5 and 7 µm and slightly increased as the number of layers increased; noting that the emulsion droplets were poly-dispersed. Another possible problem that may occur using the LbL technique is the complex formation between non-adsorbed protein and the pectin molecules. These complexes with a typical diameter smaller than 1 mm were not detected here. Result showed that the zeta potential distribution of emulsion droplets reverses from about plus (+) 30 mV (odd number of layers with SPI fibrils as outer layers) to about negative (-) 20 mV (even number of layers with HMP as outer layers) confirming the layer-by-layer adsorption based on electrostatic attraction. Comparing SEM of microcapsules with various numbers of layers, an improvement in shell strength can be seen. Indentation is observed on 1-layer microcapsules showing that there are defects on the shell. They could be formed during the drying process or they are shell defects due to incomplete coverage of materials, meaning more layers are needed to fully cover the microcapsule shell. These defects are seen less on 5-layer microcapsules. These observations indicate that the more layers the more consistent the shells and the more resistant. It is against the physical drying process. Results showed that the time of the maximum in release shifts to higher values as the number of layers of the capsules increased. We clearly see that increasing the number of layers in the shell of the capsules leads to a delay of the release of diacetyl and maximum release time as a function of the number of layers is increasing steadily which show the release can be delayed even more by adding additional layers. These results prove that the release properties of the multilayer capsules can be tuned by controlling the number of layers in the shell of the capsules. The modeling results of four different kinetic models are indicated that the Rigter–Peppas was an appropriate model for diacetyl release prediction from multilayer microcapsulation. It could be attributed that the release mechanism is mostly governed by the Swelling–Fickian mechanism.
Conclusion: In this study, the microcapsules were produced using the LbL technique and food-grade SPI fibrils and HMP. The microcapsules had a poly-disperse size distribution. No flocculation of microcapsules during applying of additional layers was observed. It was found that increasing the number of layers, decreases the release rate of diacetyl. The diacetyl release data were kinetically evaluated by zero-order, first-order, Higuchi, and Rigter–Peppas models and the results showed that the release phenomena is mostly governed by the Fickian mechanism. Since the materials are food-grade, the applications of these microcapsules can include food products or pharmaceutical purposes.
Vahid Mosayebi; Farideh Tabatabaei Yazdi; Zahra Emam-Djomeh
Abstract
Introduction: Pectin is a complex heteropolysaccharide presented naturally in the middle lamella and primary cell walls of plant tissues. Pectin is mostly composed of a linear backbone of α-(1, 4) linked D-galacturonic acid residues which are partially esterified with methyl alcohol or acetic acid at ...
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Introduction: Pectin is a complex heteropolysaccharide presented naturally in the middle lamella and primary cell walls of plant tissues. Pectin is mostly composed of a linear backbone of α-(1, 4) linked D-galacturonic acid residues which are partially esterified with methyl alcohol or acetic acid at the carboxylic acid. Pectin is widely used as a gelling agent in food systems such as jams and jellies, fruit juices, confectionaries, bakery fillings and as a stabilizer in acidified milk drinks. Black mulberry (Morus nigra.L), originating from Iran, is a juicy fruit with dark red color and slightly acidic flavor. Black mulberry has gained an important position in fruit markets and food industry due to its distinctive flavor and phytonutrients in recent years. Black mulberries can be consumed as fresh or processed into several products such as juice, marmalades, liquors, natural dyes or even be used as frozen fruit in ice cream production. However, due to short harvesting season and susceptibility to spoilage, black mulberries are mostly processed into juice besides its fresh consumption. Press cake residue or pomace is the main by-product which is generated in large amounts from the commercial juice extraction processes from berry fruits which contain several bioactive compounds and valuable ingredients including antioxidants, phenolics, pigments, pectin and so on. These berry pomaces are considered suitable for pectin recovery although their pectin content is somewhat lower in comparison to rich known sources of pectin. Recently, ultrasound assisted extraction technique, as a novel method of extraction, has gained remarkable attention due to its some advantageous effects including shorter extraction time, reduced solvent and energy consumption and higher yield and better quality of extracted compounds as compared to conventional acid extraction method. Therefore, the present work was aimed to evaluate and optimize the ultrasound assisted extraction parameters (time of extraction, ultrasound power and liquid/solid ratio) to maximize the extraction yield, degree of esterification and galacuronic acid content of pectin from black mulberry pomace using three level three factor face centered central composite design.
Materials and methods: Fresh and fully ripe black mulberry fruits were purchased from a local fruit market in Karaj (Iran) and subsequently pressed to separate pomace from juice. The obtained pomace was then vaccuum dried (until 7.8±1% moisture content), ground to obtain a homogenous powder, sieved, filled into polyethylene containers, and stored at refrigerator. Pectin extraction from this powdered pomace was carried out using an ultrasonic bath at operating frequency of 35 kHz under different parameters including extraction time (20-60 min), ultrasonic intensity (40-100%) and liquid-solid ratio (15:1 to 30:1 mL/g). The initial pH value of the solution was adjusted to 2.0 by adding 1.0 N HCl solution. At the end of extraction, extracts were quickly cooled, centrifuged, filtered using Buchner funnel, concentrated by 5 fold, coagulated with 96% ethanol (ER=1.5) and left for 8 hours in room temperature. The precipitated pectin was separated by Buchner funnel, rinsed twice with 96% ethanol, dried under vacuum (45°C) and finally powdered. The degree of esterification of pectin was determined by titrimetric method according to Bochek et al. (2001). The galacturonic acid content was quantified by the colorimetric method with m-hydroxydiphenyl reagent using a spectrophotometer at 520 nm. The intrinsic viscosity [ƞ] of pectin was determined using a capillary tube viscometer and accordingly the viscosity average molecular weight [Mv] was calculated from the Anger-Berth equation. Finally, the frequency sweep test was performed using a controlled stress rheometer to determine the values of storage modulus (G′) and loss modulus (G″). The experimental design and statistical analysis were performed using response surface methodology (RSM).
Results and discussion: According to the obtained results, the extraction yield, degree of esterification and galacturonic acid content of pectin varied in the range of 4.73-7.68%, 42.42-58.33 and 18.70-31.45%, respectively. The extraction yield of pectin was linearly affected by the extraction conditions and its value significantly increased with increasing all the studied independent variables (p
