The effect of periodate oxidation of basil seed gum and its addition on protein binding

This study attempted to determine the best point of basil seed oxidation by applying response surface methodology (RSM) with 3 factors of temperature (35-45 °C), pH (3-7) as well as time (3-7 h), at 3 levels. The produced dialdehyde basil seed gum (DBSG) was collected and its physicochemical properties were determined. Fitting of quadratic, linear polynomial equations was subsequently done by considering the insignificant lack of fit, as well as highly considerable R², in order to probe the probable relationship existing between these considered variables as well as the obtained responses. So the considered optimal related test conditions, which included pH = 3, T = 45 °C as well as Time = 3 h, were specified to produce the highest percentage of aldehyde (DBSG32), optimal (DBSG34) and the (DBSG74) samples with the highest viscosity. The results obtained by FTIR and aldehyde content determination provided the indication that dialdehyde groups were formed in a way that was in equilibrium with the considered the hemiacetal form which was dominant. Furthermore, AFM investigation related to the considered DBSG34 sample displayed over-oxidation as well as depolymerization; this might be due to the enhanced hydrophobic qualities, as well as the decreased viscosity. While the DBSG34 sample had the most dialdehyde factor group with a particular tendency for the combination having the proteins' amino group, DBSG32 and DBSG74 samples could be desirable for industrial uses owing to no overoxidation.

Investigation of the mixing ratio of quince seed gum, potato starch and gellan gum on the properties of the resulting film by Mixture Design

In this study, the impact of three different biopolymers, namely, quince seed gum, potato starch and gellan gum, at levels of zero to three, on optimizing the biodegradable film was investigated. In order to prepare the mixed edible film, the textural properties of the films, water vapor permeability, water-solubility, transparency, thickness, color parameters, acid solubility and microstructure of the made films were investigated. Numerical optimization of method variables was performed based on the maximum Young's modulus and minimum solubility in water, minimum solubility in acid and minimum water vapor permeability by mixed design, using the Design-Expert software. The results showed that the increase of the quince seed gum directly affected the Young's modulus, tensile strength, elongation to break, solubility in acid, and a* and b* values. However, the rise of the potato starch and gellan gum levels increased the thickness, solubility in water, water vapor permeability, transparency, L* value and Young's modulus, tensile strength, elongation to break, solubility in acid and a* and b* values. The optimal conditions for the production of the biodegradable edible film were selected at the levels of 1.623 %, 1.637 % and 0 % for quince seed gum, potato starch and gellan gum, respectively. The results of scanning electron microscopy showed that the film had more uniformity, coherence and smoothness, as compared to other films studied. The results of this study, thus, showed that there was no statistically significant difference between the predicted and laboratory results (p < 0.05), indicating the good fit of the model designed for producing a quince seed gum/potato starch/gellan gum composite film.

Production and Optimization of Conjugated Linoleic and Eicosapentaenoic Acids by Bifidobacterium lactis in Cold-Pressed Soybean Cake

Background and Purpose

In regard to the biosynthesis of conjugated linoleic acid (CLA) and eicosapentaenoic acid (EPA) by some bacteria, the objective of this study was to evaluate the efficiency of solid-state fermentation based on soybean pressed cake (SPC) to produce CLA and EPA by Bifidobacterium lactis. The objective of this study was to evaluate the efficiency of solid-state fermentation based on SPC to produce CLA and EPA by B. lactis.

Methods

Process conditions including humidity, inoculation level, and temperature parameters were optimized by adopting the response surface methodology (RSM) method (response surface method) and the design expert software. Accordingly, a homogeneous SPC paste substrate at 60, 70, and 80% humidity was prepared with different inoculation levels at 30, 37, and 44°C to assess the strain behavior. The introduced SPC consisted of 60% humidity, 2% inoculation level at 37°C, and 60% humidity, and 4% inoculation level at 30 and 44°C; it also included 6% inoculation level at 37°C, 70% humidity at 2% inoculation level, at 30 and 44°C, and 4% inoculation level at 37°C. Also, SPC with 80% humidity at 2% and 4% inoculation levels, and at 30 and 44°C was obtained. To confirm the accuracy of the conditions, an experiment was conducted according to the defined requirements.

Results

The results were compared with the predicted data, which showed a significant difference. Under optimized conditions, with an inoculation level of 4% on the SPC medium with 70% humidity and at 37°C, B. lactis strains could yield 9cis-, 11 trans-linoleic and eicosapentaenoic at 0.18 and 0.39% of the total fatty acids.

Conclusion

So, the potential benefits of using SPC as an inexpensive substrate for the commercial production of CLA and EPA should be noted.

Monitoring of Aflatoxin M1 in milk using a novel electrochemicalaptasensorbased on reduced graphene oxide and gold nanoparticles

Accurate and rapid detection of Aflatoxins as one of the most hazardous compounds in foodstuffs is very important. In this study, a label-free electrochemical aptasensor was developed to identify aflatoxin M1 using a reduced graphene oxide (rGO) and gold nanoparticles (AuNPs)-based pencil graphite electrode (PGE). The morphological characteristics of the electrode surface were investigated using SEM and rGO functional groups were confirmed by FTIR. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques were used to characterize various stages of electrode modification. In order to optimize the impedimetric response of the aptasensor, aptamer immobilization time, aptamer concentration, and binding aflatoxin M1 with aptamer time were optimized. Under optimal conditions, the linear concentration range of 0.5-800 ng/L and limit of detection (LOD) of 0.3 ng/L were obtained for aflatoxin M1 by measuring the resistance charge transfer data. Finally, the fabricated aptasensor was successfully used to measure AFM1 compared to HPLC method.

Optimization of fortified sponge cake by nettle leaves and milk thistle seed powder using mixture design approach

Powdered nettle leaf and milk thistle (MT) seed were added to the cake batter with certain percentages selected by the Design-Expert v. 10 software (0-25, 25-0, 18.75-6.25, 6.25-18.75, and 12.5-12.5). Addition of nettle and MT seeds to the cake reduced the moisture content, volume, and springiness and increased hardness of the samples. 12.5% nettle-12.5% MT seed had the least hardness and the highest amount of springiness and cohesiveness. The highest BI, WI, SI, L*, a*, and b* and the lowest ΔE were observed in 12.5% nettle-12.5% MT seed and 25% MT seed samples, respectively. Antioxidant activity and antimicrobial properties were increased in all samples compared to the control sample, so that 6.25% nettle-18.75% MT exhibited the highest antioxidant activity and antimicrobial properties. The highest levels of quercetin and silymarin were observed in 25% nettle and 25% MT seeds, respectively. In the sensory evaluation, 12.5% nettle-12.5% MT seed took the best scores regarding flavor, texture, color, and overall acceptance. Based on the lowest hardness, 13.65% nettle-11.34% MT seed was determined as optimized points by the software, which was equivalent to desirability of 0.72. The optimum sample contained 62.90 mg quercetin and 886.70 mg silymarin. According to the HPLC analysis results, consumption of 10 optimal cakes daily could theoretically decrease the blood sugar level, which requires further studies. The remaining amount of quercetin and silymarin in 2.5 g of nettle leaves and 2.5 g of MT seeds after heating was 11 and 19 mg, respectively. In other words, heat did not have much effect on the destruction of quercetin and silymarin.

Different drying methods of Pistacia Atlantica seeds: Impact on drying kinetics and selected quality properties

The effect of different drying procedures on the quality characteristics of Pistacia atlantica subsp. kurdica is addressed in this work. Using five different drying methods include microwave, oven (40 and 60°C), sun, and shade, P. atlantica were dried. The variations in moisture content, drying rate, major components of essential oil, and texture property were assessed at the start and at the end points of the drying process. Comparison of the drying methods indicated that microwave drying to be most effective in lowering moisture content, while the shade drying had the lowest rate among methods. In the case of microwave, the dried seeds had highest brittleness, while the highest score for the penetration force was observed in oven 40°C. Regarding major elements of the essential oil (α-pinene, α-terpinen-4-ol, myrcene, β-ocimene, β-caryophyllene, and limonene), there were no significant differences between the five drying techniques, nor compared to the fresh sample. To model the drying process, six thin-layer drying kinetic models were chosen. It was found that the Midilli-Kucuk model was the most suitable for explaining the drying curve of oven 40 and 60°C, microwave, and sun methods; Wang and Singh model was excellent to explain thin-layer shade drying behavior of the P. atlantica seeds. In conclusion, in this study, an opportunity is represented to apply the most effective procedures to decrease the drying period and to achieve a product with appropriate safety and quality features.

The influence of fat substitution with κ-carrageenan, konjac, and tragacanth on the textural properties of low-fat sausage

Reducing the fat content of meat products and producing healthier products is considered as an important matter in politics in prevention of many hazardous diseases and providing consumers' health. The aim of this study was reducing the fat in fatty sausages based on oil reduction and using fat substitutes, including κ-carrageenan, konjac, and tragacanth, and comparing them according to their texture characteristics. κ-carrageenan, konjac, and tragacanth gums were used at four different levels (0.0, 0.5, 1.0, and 1.5) as the fat substitutes in producing low-fat sausage with 70% reduction based on formulated oil. Texture profile analysis (Hardness, Gumminess, Springiness, and Chewiness) was performed in this study for analyzing the texture characteristics, in 1-, 10-, 20-, and 30-day time intervals after production. The results showed that producing low-fat sausage was possible using all the three gums, among the low-fat samples of which, the texture samples containing konjac were more favorable. Textural properties indicated that fat reduction increased in firmness and gum addition can partially compensate deficits in rheological properties, although during the storage, low-fat sausages without any gum have highest decline in Hardness. Konjac gum illustrated the best theological properties between treatments.

Using Thymus carmanicus and Myrtus communis essential oils to enhance the physicochemical properties of potato chips

The aim of this study was to evaluate the antioxidant effects of the essential oils of Myrtus communis leaves and Thymus caramanicus aerial parts in order to improve the physicochemical properties of potato chips. Sunflower oil without any antioxidant (control group) was fortified with BHA or TBHQ antioxidants (200 ppm), and M. communis or T. caramanicus essential oils (3,000 ppm). The effects of the antioxidant behavior of these compounds on the physicochemical properties of potato chips were analyzed by measuring peroxide value (PV), acid value (AV), and thiobarbituric acid (TBA). In addition, changes occurring in oxidation stability, texture, and color were evaluated. The results revealed that samples containing either M. communis or T. carmanicus showed a significant decrease in PV, as compared to the control sample. Compared with the control, the extracted oil of potato chips with M. communis or T. carmanicus led to the significant reduction in AV (p < .05). The results also revealed the addition of the essential oils of M. communis or T. carmanicus was obviously effective in preventing the TBA increasing value. Based on the results obtained by the Rancimat test, either T. carmanicus or M. communis essential oils could significantly increase the shelf-life of potato chips, as compared with the control sample (p < .05). The hardness of potato chips was decreased in M. communis or T. carmanicus groups (p < .05), as compared to the control sample. Neither M. communis nor T. carmanicus essential oils had any negative effects on the lightness values, as compared to the control (p > .05). Based on the results, the physicochemical properties of potato chips could be improved with the addition of these essential oils.

The effect of inulin as a fat substitute on the physicochemical and sensory properties of chicken sausages

Due to its high thermal resistance and compatibility with the sausage emulsion system, the long‐chain inulin can be used as a fat substitute in the formulation of this product. This study was conducted to investigate the effect of inulin on the physicochemical, textural, and sensory properties of chicken sausages. The study included treatments of 25%, 50%, 75%, and 100% substitution. After preparing the samples, their physicochemical, textural, calorimetric, and sensory properties were evaluated. The treatment of 100% substitution of inulin had the maximum amount of sugar (29.90%), moisture (72.63%), protein (51.34), ash (6.95%), and salt (4.02%) (dry basis). The fat content was decreased with the increased levels of inulin substitution (p < .05). The increased amount of inulin reduced hardness, cohesiveness, gumminess, and stringiness, but increased springiness and chewiness up to the 25% substitution of inulin. The highest color difference and hue angle were related to 100% substitution treatment. The sensory evaluation of the samples showed that with the increase in the amount of inulin, the mean scores of the factors including color, appearance, and texture were increased, but the mean scores of smell and mouthfeel were decreased. Overall, the substitution of the entire fat existing in the formulation of the sausage with inulin led to the best physicochemical, textural, colorimetric, and sensory results. The use of inulin could be recommended as a fat substitute in the formulation of chicken sausages.

The Evaluation of saccharose replacing by adding stevioside-maltodextrin mixture on the physicochemical and sensory properties of Naanberenji (an Iranian confectionary)

Stevia is a natural, non‐nutritive sweetener can replace sugar in your diet to control diabetes and aid in weight loss. Naanberenji, an Iranian traditional cookie, is a well‐reputed confectionary containing high sucrose and calorie value, for this reason its consumption in healthy diet has been restricted. In this study, the effect of sucrose replacement by stevioside‐maltodextrin mixture on physicochemical properties of Naanberenji was evaluated in four replacing levels including 25%, 50%, 75%, and 100%. Results of texture evaluation revealed that hardness increases due to adding stevioside‐maltodextrin (p < .05). Color analysis also showed that browning index by adding more mixture reduced. Moreover, the results of sensory analysis showed that treatment containing 25% stevioside‐maltodextrin was the most similar sample to control and 23.06% reduction in sugar consumption achieved in this level of replacement. Therefore, its physicochemical properties (peroxide, acidity, chemical compounds, and hardness) were measured. According to the results, calorie amount decreased by 7.27 %. While there was no significant difference in the acidity of the aforesaid sample, peroxide results exhibited significant differences. Analysis of Farinograph plot revealed more water binding in comparison to control sample.

Optimization low-fat and low cholesterol mayonnaise production by central composite design

In this study, the optimized process variables for mayonnaise low in cholestrol and fat, which contained soy milk as a yolk substitute with different levels of Xanthan gum, Zodo gum, and oil, were determined by response surface methodology using a central composite design. Polynomial equation was fitted with an insignificant lack of fit factor in order to study the relationship between variables and responses including apparent viscosity, consistency coefficient, flow index, firmness, and stability of mayonnaise sauces. Results showed that increased amounts of Xanthan gum, Zodo gum and oil led to an increase in the apparent viscosity, the consistency coefficient, the firmness/emulsion stability of the mayonnaise, while the mayonnaise flow index was reduced. The interaction effects between Xanthan gum and Zodo gum, and between Xanthan gum and oil were significant on apparent viscosity. Optimum conditions of variables were obtained due to response ranges of commercial mayonnaise as following ingredients: 0.25% Xanthan gum, 3.84% Zodo gum, 37.50% oil, and with the replacement of 63.61% soy milk. Yolk, however, was replaced with soy milk without emulsion fracture up to 100%. This study showed good potential for Zodo gum native mixed with Xanthan gum and soy milk to be used as a fat and yolk substitute in mayonnaise, respectively.