Food Engineering
Fatemeh Sabzmeidani; Masoud Taghizadeh; Mohammad Saleh Hemati Hasan Poor
Abstract
IntroductionIce cream is a frozen product, which is obtained from milk by adding compounds such as sweeteners, emulsifiers, stabilizers and flavoring agents. The structure of ice cream is a complex physicochemical system composed of three phases: liquid, solid and gas. Scientific results have shown that ...
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IntroductionIce cream is a frozen product, which is obtained from milk by adding compounds such as sweeteners, emulsifiers, stabilizers and flavoring agents. The structure of ice cream is a complex physicochemical system composed of three phases: liquid, solid and gas. Scientific results have shown that there is a connection between high fat consumption and cardiovascular diseases. Considering that ice cream is an almost fatty product and is particularly popular among people in the society, there is a greater demand for consuming low-fat varieties of this product. The food industry is also looking for new alternatives to minimize the negative effects of fat reduction on quality of ice cream. Hydrocolloids, are carbohydrate-based fat substitutes, which can mimic the mouthfeel and flow characteristics of fat cells due to their emulsifying and water binding capabilities. Eremurus luteus is one of the rhizome plants belonging to the Asphodelaceae family, cultivated around the world, including Iran. Cerise root gum is a new source of hydrocolloid with a glucose to mannose ratio of 1:1 to 1 from the family of glucomannans. The intrinsic viscosity of this gum was measured as 6.32 and 6.35 dl/g according to Huggins and Kramer equations, respectively, and it has the highest foam stability in concentrations of 0.2 to 0.5%. The rheological properties of cerise root gum have proven its important role as a new thickener, stabilizer and foaming agent.Materials and MethodsIn this research, sterilized and homogenized milk (1.5% fat) from Mihan Dairy Industries Company, sterilized and homogenized cream (25% fat) from Pegah Khorasan Dairy Industries Company, emulsifier 471 E from Beldom Belgium Company, powdered skim milk from Pegah company.Sugar and vanilla from confectionery store. Serish root gum was prepared according to the method of Salahi et al. (2020).The amount of ingredients required for the normal sample (high-fat control) was determined based on primary sources, including 10% fat, 11% fat-free milk solids, 12% sugar, 0.25% stabilizer, 0.15% emulsifier and 0.1% vanilla. According to the definitions for reduced-fat ice cream, 75% fat reduction was made from the normal sample (10% fat). In this regard, the investigated treatments were as follow: the amount of fat (2.5% fat: L), the type of gum (SRG) and the concentration of gum (at four levels: 0.2, 0.3, 0.4, 0.5%) compared to the control sample as high fat (10% fat: F).First, the liquid ingredients, including milk and cream, were continuously stirred while heating up to a maximum of 5 °C. After that, the mixture of solid materials (sugar, milk powder, gum, etc.) was added to the liquid part and mixed with a stirrer for three minutes after dissolving thes solids. The resulting mixture was pasteurized at 80°C for 25 seconds and homogenized with a homogenizer at 22,000 rpm for 1 minute and transferred to a water, salt, and ice bath and cooled to 50°C. Then, it was kept in the refrigerator at a temperature of 5°C for 24 hours. Finally, the mixture was transferred to a non-continuous ice cream machine for 15 minutes for the freezing stage, and the samples were poured into special containers with lids and coded, and placed in a freezer at -18 °C for at least 24 hours.Results and DiscussionBy adding gum and increasing its concentration, the amount of apparent viscosity, consistency coefficient, yield stress, plastic viscosity, textural characteristics (hardness, adhesion, continuity and apparent modulus of elasticity) increased. In the sensory evaluation section, the characteristics of creaminess, sweetness, viscosity, roughness, coldness and hardness were evaluated by transient dominant sensation test and these changes were significant in most cases. Sample containing 0.3% gum had the highest overall acceptance after the control sample compared to other samples. The results showed that these variables have the ability to simulate rheological properties (apparent viscosity, consistency coefficient, yield stress and plastic viscosity), melting speed and sensory characteristics such as creaminess, roughness, cryogenicity, viscosity, hardness and overall acceptance of the control sample with high fat as effective factors on the texture production process and the mouthfeel of the product in low-fat ice creams. On the other hand, due to the absence of significant differences between the data obtained from the pH and dry matter measurement tests, the applicability of Serish gum can be confirmed as a fat substitute.ConclusionThe examined samples all showed the loosening behavior with cutting. In the sample containing 0.2% gum, the melting speed increased (from 0.32 to 0.39), also with the increase in the amount of gum in the samples, the freezing temperature decreased by one degree Celsius (from39.4 to 39.5). Overall acceptance, pH and dry matter did not change significantly, which indicates the usefulness and applicability of this method. Also, regarding the rheological characteristics, the highest consistency coefficient in the 0.5% gum sample was 2.2605, similarly, the highest yield stress was in 0.5% gum sample and was 6.7076 pa. Similarly, the highest amount of Plastic viscosity and apparent viscosity belonged to the sample containing 0.5% gum. It was also shown that in the rheological characteristics, with the increase in the amount of gum in the samples, the amount of the relevant parameter increased significantly, and in all these parameters, sample containing 0.2% showed a lower amount than the control sample.
Reyhaneh Dakhteh; Mohammadreza Khani; Shahriar Dabiriyan
Abstract
Introduction: Because of the relationship between fat intake and obesity and the incidence of cardiovascular diseases, the demand for low-fat products has been increased. There are several methods to produce low fat products, which one of these methods is the use of fat replacer. The present study was ...
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Introduction: Because of the relationship between fat intake and obesity and the incidence of cardiovascular diseases, the demand for low-fat products has been increased. There are several methods to produce low fat products, which one of these methods is the use of fat replacer. The present study was aimed to partial substitution of fat in table cream by Qodume shirazi (Alyssum homolocarpum) and Persian (Amygdalus scoparia) gums. Materials & Methods: The fat content of cream was decreased from 25% (in control sample) to 18% and 15%, and each of these gums were added to the low-fat cream formulation in 0.2%, 0.3%, and 0.4% (w/w), separately to make 12 treatments. All samples were examined for physicochemical (including pH, acidity, dry matter, moisture, synersis, and viscosity) and organoleptic (including color, aroma, taste, texture and overall acceptability) properties. Results and Discussion: The results showed that the effect of type and amount of gums was significant for the pH, acidity, dry matter, moisture, syneresis, and viscosity of produced samples (P<0.05). In both types of cream (with 15 and 18 percent fat), pH of treatment containing 0.4% Qodume gum (6.81) was significantly higher than control (6.69) and other treatments (P<0.05). Moisture content of the control sample (68.7%) was lower than other treatments (73-78.7%) but dry matter of the control sample (31.3%) was higher than other treatments (21.2-26.9%) and in both creams containing 18% and 15% fat, the higher dry matter was devoted to sample containing 0.4% of Persian gum. The viscosity of cream with 18% fat containing 0.4% Qodume shirazi gum (21915 cP) and Persian gum (21919 cP) was significantly higher than the control sample (21507 cP) and other treatments. Moreover, syneresis of treatments with 18% fat containing 0.4% Qodume and Persian gums (0 ml), and also cream sample with 15% fat containing 0.4% Qodume gum (0 ml) was not observed as in the control sample (P>0.05). Evaluation of sensory properties revealed that the type of gums only had significant effect on color and the effects of cream type and amount of gums were mostly significant on texture and overall acceptance. In general, low-fat cream with 18% fat containing 0.4% Qodume and Persian gums had showed the best physicochemical and sensory results comparing to other treatments.
Shadi Basiri; Fakhri Shahidi
Abstract
Introduction: Morus Alba, known as white mulberry, is a short-lived, fast-growing and small to medium sized mulberry tree, which grows to 10–20 meters tall. The species is native to northern China, and is widely cultivated and naturalized elsewhere. The fruit is 1–2.5 cm long in the species in the ...
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Introduction: Morus Alba, known as white mulberry, is a short-lived, fast-growing and small to medium sized mulberry tree, which grows to 10–20 meters tall. The species is native to northern China, and is widely cultivated and naturalized elsewhere. The fruit is 1–2.5 cm long in the species in the wild, it is deep purple, but in many cultivated plants it varies from white to pink, being sweet and bland. The fruits are also eaten, often dried or made into wine or vinegar. In traditional Chinese medicine, the fruit is used to treat prematurely grey hair, to tonify the blood, and treat constipation and diabetes. White mulberry is a fruit with high nutritional quality. The shelf life of mulberry is short due to its high moisture content. Dried mulberry and its molasses are popular products from mulberry fruit. Hydrocolloids are used in fruit snacks formulations to create novel texture, increase stability for their water-holding capacity, improve texture and have an impact on flavor release and other structural and sensory properties in the respective products. Hydrocolloids are also widely used in the food industry as thickeners, stabilizers and gelling agents in various products including ice cream, sauces, jellies and pastille products. Guar gam is kind of long-chain galacto-mannan with high molecular weight, obtained from endosperm of guar plant. This type of synergistic behavior among polysaccharides is commercially valuable, because it creates a novel texture and a more desirable structure. The aim of this research is to produce mulberry pastille as a novel and value added product with long shelf life. Beside it can be introduced as a healthy snack replacing sugar. Materials and methods: The materials include mulberry puree, hydrocolloids (Gelatin and guar) and citric acid. Berries were collected from the gardens around Mashhad (Iran). Guar was purchased from Sigma Chemical Company, citric acid was purchased from Merk Chemical Company, Germany. Gelatin (0, 1, and 2 %) and Guar (0, 0.5, and 1 %) were used for pastille formulations. To produce fruit pastille based on mulberry puree, the prepared puree was mixed into hydrocolloids. After measure pH and moderating to PH = 4.3 by adding acid citric in 40 % concentration and controlling the Brix degree to constant Brix of 45, the mixture was prepared. Then the prepared mixture was poured into a network framework of steel origin in the cavities with 1.2×1/2 and the molds were hold in the refrigerator for 2 hours with 4°C to fasten the gel. The obtained gel was taken out of the mold cavities and placed in a glass plate. The samples were then dried at 70° C in a hot air drier with airflow rate of 1.5 m/s for 6 hours. The samples were evicted every 30 minutes. Parameters such as color, sensory and textural characteristics of samples were investigated. Statistical design was 2 factors factorial with three replicates adopted completely randomized design. Results and Discussion: The results of texture evaluation showed that increasing guar gum improves the cohesion, elasticity and chewiness of the samples, while their adhesion were decreases. Conclusion: Mulberry pastille including 1% Guar and 1% Gelatin having the lowest amount of firmness, adhesion, chewiness and suitable color characteristics, was determined as the best formulation among the other investigated samples.
Hossein Jooyandeh; Vahid Samavati
Abstract
Introduction: Accumulation of free radicals could lead to permanent oxidative destruction of organisms by attacking macromolecules and organelles of the body, thus causing organism aging, fatigue and degenerative diseases. Therefore, discovering and developing safe and non-toxic natural antioxidants ...
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Introduction: Accumulation of free radicals could lead to permanent oxidative destruction of organisms by attacking macromolecules and organelles of the body, thus causing organism aging, fatigue and degenerative diseases. Therefore, discovering and developing safe and non-toxic natural antioxidants has been an interesting topic in recent decades. Compared to synthetic antioxidants, extracts from plant resources usually have quite stable constructions and great antioxidant activities, and can easily be absorbed without dangerous immunoreactions. Many antioxidant compounds, naturally occurring from plant sources, have been identified as free radicals or active oxygen scavengers. Malva neglecta (MN), which is known as Panirak/Tooleh in Iran is an annual and herbaceous plant. The leaves and flowers of MN are used in traditional phytotheraphy and in treatment of cough, respiratory system and digestive system problems. The objective of this study was to optimize process conditions of extraction in order to obtain the highest yield from crude extract of MN leaves and identify its antioxidant properties. Materials and methods: Three-variable-three-level Box-Behnken design-response surface methodology (BBD-RSM) with five replications at central point was used to optimize the extracting parameters of crude extract from the MN leaves including extraction time (1-8 h), extraction temperature (50-100°C), and the water/solid ratio (3-30). The ability of extracted materials to scavenge the free radicals of DPPH, OH and super oxide was also evaluated by chemical analysis. Results and Discussion: All three independent variables effected the yield of crude extract of MN leaves. The extraction yield of MN crude extract significantly increased from 5.90% to 8.01% with extraction time varying from 1 h to 6 h. However, the yield was not altered meaningfully, as the extraction time was increased from 6 h up to 8 h. This may be due to degradation of the polysaccharides because of the extended extraction time. The extraction process was performed with temperatures from 50 °C to 100 °C, with the other extraction variables such as ratio of water to raw material and extraction time fixed at 13 ml/g and 3.5 h, respectively. The extraction yield of crude extract increased with increasing extraction temperature and peaked at 7.89 at 100 °C. Different ratios of water to raw material have considerable effect on extraction yield. In this study, we used ratios of water to raw material from 3 to 30 ml/g, with fixed parameters (extraction time and extraction temperature at 3.5 h and 75 °C, respectively). Extraction yield increased noticeably from 6.10 to 8.10 with ratio of water to material varying from 3 ml/g to 24 ml/g. As extraction time, at the higher experimental levels, as the ratio of water to raw material was increased (from 24 up to 30 ml/g) the yield of crude extract was not changed considerably. Under the appropriate condition of ratio of water to raw material, the crude extract molecules can swell thoroughly, and more compounds could dissolve in water to improve extraction yield. The determination coefficient (R2 = 0.9897) suggested that the model was valid, implying that 98.97% of the variation could be explained by the fitted model. The adjusted determination coefficient was used to evaluate the correlation between the experimental values and predicted values, and the outcome (R2Adj= 0.9794) suggested that the correlation was significant. The f-value (1.49) for “the lack of fit” indicated that the “lack of fit” was not significant relative to the pure error (p > 0.05). The CV for yield of MN leaves was 0.64%, which defined a good reliability of the experimental values. The adequate precision value 21.61 and PRESS 0.42 for our model indicated an appropriate model could be designed. On multiple regression analysis, the quadratic polynomial equation for the independent variables and response variable expressed as follows: Y =7.82 + 1.025X1 + 3.241667X2 + 2.031X3 + 0.525X1X2 - 0.7X1X3 + 0.675X2X3 – 0.206X12 – 0.21833X22 Where, Y is extraction yield (%); X1, extraction time (h); X2, extraction temperature; and X3, ratio of water to raw material (ml/g) Statistical analysis of the results showed that the optimal conditions for higher extraction yield were extraction time: 6 h, extraction temperature: 90oC, and the ratio of water to raw material: 19. Under these conditions, the experimental yield was 9.22% ± 0.47%, which well matched the predicted value (9.18%), under these conditions; the experimental yield was 9.18%. Furthermore, results obtained from chemical analysis showed that DPPH, OH and super oxide scavenging of MN crude extract increased rapidly with increasing of its concentration. DPPH scavenging rate of the crude extract was more than BHT standard (89% vs. 78%) at their maximum equivalent concentration (300 ppm). Furthermore, OH and super oxide scavenging ability of MN crude extract (87% and 91%, respectively) were significantly more than ascorbic acid standard solutions (74% and 81%, respectively) at their highest experimental concentrations (150 ppm). Based on our results, components extracted from Malva neglecta leaves may introduce as an antioxidant and free radical scavenger. This study could help food industries to add a new source of hydrocolloid with certain functionality as an alternative additive in different foods, cosmetic and pharmaceutical products.
Behnam Fiyuzi; Mostafa Mazaheri Tehrani; Esmail Khazaei
Abstract
Introduction: Due to the lack of proper harvest, packaging, transport and storage, about 30% of country dates production cannot be directly absorbed into the consumer market and must be exchanged to valuable products in transformation industries.Hydrocolloids are used in fruit snack formulations to create ...
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Introduction: Due to the lack of proper harvest, packaging, transport and storage, about 30% of country dates production cannot be directly absorbed into the consumer market and must be exchanged to valuable products in transformation industries.Hydrocolloids are used in fruit snack formulations to create novel texture, increase stability due to their water-holding capacity, improve texture and have an impact on flavor release and other structural and sensory properties in the respective products. Gelatin is a gel forming hydrocolloid. Xanthangum is a kind of long-chained polysaccharide with high molecular weight. LikeXanthan and guar gums can also interact with some polysaccharides such as gelatin, agar and carrageenan synergistically leading to increased viscosity or gel forming power. This type of synergistic behavior among polysaccharides is commercially valuable, because it creates a novel texture and a more desirable structure.This study on viscosity and textural changes caused by using a mixture of gums in food formulations is important and will affect the cost of various stages of the process.Material and methods: The initial materials containing date(Shahani variety), condensed whey(brix=35) were provided from Asali Mod compony, Xanthan gum from Sigma company. powdered glucose and date were bought from Mashhad bazar.In order to produce gel based on date puree, the date were fist washed up, peeled and cut into pieces. Then the pieces were grinded. The prepared puree was mixed with hydrocolloids and sweeteners at 70°C with specific ratios. The mixture was then poured into stainless steel mesh molds with cavity dimensions of 1.2 cm × 2 cm × 2 cm and the molds were kept at 4°C for 2 hours to form the gel. Then the obtained gel was taken out of the mold cavities and the samples were dried at Environmental drier with 1.5 m/s airflow rate. In this research, the produce of jelly viable products based on date puree by the different rates of gelatin hydrocolloids in two levels (6 and 8%) and Xanthan in two levels (0.25 and 0.75%) and condensed whey in three levels (5, 10 and 20%) was studied. Dependent variables were consisting of moisture content, water activity, PH, Brix, protein, ash, texture assessment and color parameters. In final has done the sensory evaluation.To measure pH, pH meter (Hana, Portugal) was used. The measurement of mixture Brix was performed by an optical refract meter (Carlze, Germany).Moisture, protein and ash were measured according to the Iran national standard.In order to determine the water activity of the samples, equal weights of the samples were grinded and the water activity was measured by a aw meter (Testo model 200, England) at 20°C. Texture profile analyzer (QTS25 CNS Farnell England) equipped with a software was used to determine the textural properties of the samples. Samples were compressed and decompressed in two reciprocating cycles by a round plate cylindrical probe with 3.5 cm diameter, 1 mm/s probe speed and 5 g force to 30% initial height. Histological properties obtained from force-deformation curve are as follows: Hardness, Cohesiveness, Elasticity, Adhesiveness and Chewiness.In order to measure color parameters of samples, three samples were choose randomized from each formulation, and pictures were taken with 90 angle and pictures were saved with IPG format. The other stages of picture processing were done by ImageJ 1.40g software.Sensory test was performed with the judgment of 10 trained panelists. In order to evaluate the samples. A 9-point Hedonic method (1: very undesirable - 9: very desirable) was used. 5 sensory attributes (color, texture, flavor, odor and overall acceptance) were evaluated.This study was triplicated through a completely randomized design. Gelatin hydrocolloids in two levels (6 and 8%) and Xanthan in two levels (0.25 and 0.75%) and condensed whey in three levels (5, 10 and 20%)were considered as the independent variables and a design composed of 12 formulations was created. SPSS software was used for the statistical analysis of the parameters. Mean of the replicates were compared via the multi-range Duncan`s test at 95% confidence level.Results and discussion: The obtained results showed that with increasing of condensed whey decrease the PH formulation but ash, moisture, water activity and the rate of protein in samples significantly have increased. Also effect of Xanthan and gelatin had an increase trend in water activity of samples. Also with increasing every three variables in formulation, brix had an increase trend. According to results with increasing hardness gelatin has increased the chewing and continuity feature of texture but adhesion had a decreasing trend. The increasing of Xanthan formulation led to increase of elasticity, context chewing of gum and decreasing of samples. Colorimetric results in method of Image processing were not significant on none of colorimetric variables. But in generally with increasing hydrocolloids in formulation had decreasing the light intensity and L*had a decreasing process. Sensory evaluate shows samples containing of 20% whey have less general acceptance. Also the samples containing of highest percentage of hydrocolloids allocated to themselves the less of rating flavors and aromas.
