Journal of Food and Bioprocess Engineering
Volume:3 Issue: 1, Winter-Spring 2020

In this study rhubarb stem slices were dried as single layers with thickness of 3 mm in the inlet air temperature range of 50-70  and air velocity of 1 ± 0.2 m/s in a laboratory scale cabinet dryer. The effect of drying air temperature on the drying characteristics was determined and the relationship between the drying parameters with temperature and moisture content was examined. Moisture transfer from rhubarbs slices was described by applying the Fick’s diffusion model. The effective diffusivity changes between 4.56×10-11 and 15.97×10-11 m2/s within the given temperature range and as the temperature increased so did the effective moisture diffusivity.  An Arrhenius relation with activation energy values of 57.4638 kJ/mol expressed the effect of temperature on the diffusivity. The experimental moisture loss data were fitted through 10 thin-layer drying models available in the literature. The models were compared based on the coefficient of determination, mean bias error, root mean square error, and the reduced chi-square between the observed and predicted moisture ratios. The Midilli et al. model has shown a better fit to the experimental drying data as compared to other models.

Nowadays, consumers become interested to use the substitution of natural preservatives instead of chemical preservatives. It has been proven that pomegranate peel contains large amounts of antimicrobial and antioxidant compounds. In this study, the antimicrobial effect of ethanolic extract of pomegranate peel was evaluated on total microbial count, mold and yeast and Lactobacillus plantarum during 3 months storage of thousand islands dressing at 4°C. The treated sauce samples were containing different concentrations (0.05, 0.1 and 1%) of pomegranate peel extract and 0.07% sodium benzoate, potassium sorbate mixture (BS) as control. All samples were inoculated with bacterial suspension containing 105 cfu/mL of L. plantarum. MIC and MBC of pomegranate peel extract on L. plantarum were obtained 1 mg/mL. All concentrations of pomegranate peel extract significantly decreased total bacterial count (p < 0.05). The results showed that adding 0.05% pomegranate peel extract reduced 2 Log cfu/g of total mold and yeast counts compared to the control sample in souse. There was no significant difference of adding different concentration of extract on the survival of L. plantarum (p > 0.05). Adding 0.05% pomegranate peel extract did not cause undesirable sensory attributes. Pomegranate peel extract can increase the thousand islands dressing shelf life by its antimicrobial effects as a natural antimicrobial agent and preserving the probiotic properties of the product.

Aloe vera gel is widely used as a functional ingredient in food processing. This gel is very unstable due to its high water activity. Drying process can be used to obtain shelf stable products. Response surface methodology was used to assess the effects of solution concentration (30-60% w/w), solution temperature (30-50°C) and immersion time (4-6h) at atmospheric pressure and constant solution to sample ratio (10:1) on water loss (WL), solid gain (SG), weight reduction (WR), vitamin C content (VCC) and the total phenolic content (TPC) of Aloe vera gel. The optimized conditions of osmotic dehydration combined with hot air drying were 60% (w/w) solution concentration, 30.2°C solution temperature and 349 min immersion time. Under these conditions water loss, solid gain and weight reduction found to be 72.67 (g/100g), 5.33(g/100g) and 67.34 (g/100g), respectively. The vitamin C and TPC of the osmo-air dried gel were 12.70 mg/100g DM and 11.33 mg GAE/100g DM, respectively.

Using biocomposites containing wheat straw (WS) and synthetic polymers like polyethylene (PE) has gained tremendous popularity, but its application in the packaging industry is not substantial. Due to the prevalence of raw WS color which manifests itself in the WS/LDPE biocomposite, the present investigation is dedicated to fabricate a bleached WS/LDPE composite. Thus, raw WS and the pulp of WS were treated with three levels of xylanase, five concentrations of hydrogen peroxide and five levels of sodium dithionite. The bleached raw WS and its pulp were used to fabricate WS/LDPE composites and their colorimetric properties were measured using L*, a*, and b* coordinates. The results indicated that "bleached raw WS with 4% H2O2" and "bleached WS pulp with 10 units of xylanase and by addition of 1% H2O2" demonstrate the highest degree of lightness based on L* value. Then, 40% of above mentioned treatments were blended with LDPE to develop a biocomposite using a twin screw extruder. Further, lightness index and the mechanical properties of the final composites were measured. Results indicated that the composites containing unbleached raw WS had the lowest and the bleached WS pulp with 10 unites of xylanase and 1% H2O2 had the highest L value amongst all treatments. Also the raw WS/LDPE and the bleached raw WS/LDPE composites had the highest and the lowest tensile strength, respectively. It needs to be mentioned that the flexural strength of all treatments was higher than the control, whereas the impact resistance of them was lower than the control.

In this study, the effect of infrared (IR) on decontamination of Bacillus cereus in cardamom seeds were determined at difference IR radiation powers (100, 200, and 300 W), different sample distances from radiation source (5, 10 and 15 cm) and various holding times. The most successful reduction in B. cereus numbers (5.11 log CFU/g) was achieved after a holding time of 8 min at 300 W IR power and 15 cm distance. Data were analyzed to predict antibacterial effects of IR against B. cereus in cardamom by artificial neural network (ANN) model. The developed genetic algorithm-ANN (GA-ANN), which included 12 hidden neurons, could predict B. cereus population with R2 = 0.908. The results indicated that GA-ANN model could give good prediction for the population of B. cereus. Sensitivity analysis results showed that IR irradiation time was the most sensitive factor for the prediction of B. cereus population.

Both synthetic and natural antioxidants are using in the food industries. The evaluation of the former showed its potential carcinogenic effects. So, different studies focused on natural materials as the rich source of antioxidant compounds. The aim of the present study was to evaluate some chemical properties of watermelon peel (WMP). So the minerals content, physicochemical parameters, antioxidant activity, total phenolic content, crude protein, fat, fiber, and ash determined in the WMP sample. The results showed that, watermelon peels contain protein (6.77 g/100g), fat (0.92 g/100g), ash (13.2 g/100g), fiber (24  g/100g), sodium (53.59 mg/100g), potassium (2074 mg/100g), calcium (468 mg/100g), copper (0.59 mg/100g), iron (12.08 mg/100g), magnesium (164.48 mg/100g), zinc (0.91 mg/100g) and phosphorus (107 mg/100g). It also indicates a significant free radical scavenging activity (IC50 of 147.30 mg/kg) and total phenolic content (2.47 g/100g). Finally, the WMP can consider as a good source of natural polyphenols, antioxidants and minerals.

The aim of this study is to evaluate the effects of thermal processing of virgin olive oil, canola and frying oil on chemical oxidative indices (peroxide, p -anisidin value and oxidative stability), acid value and fatty acid compositions. The oil samples were exposed to heat treatment at 180 °C and qualitative parameters were determined at 0, 60, and 90 min after thermal processing. The results indicated that the parameters of acidity, p -anisidin value increased over time (p < 0.05). Oxidative stability at 110 °C was also analyzed using Rancimat. Resistance to oxidation in frying and canola oils reduced (p < 0.05) faster than that in virgin olive oil due to presence of sterolic compounds with antioxidant properties in olive oil that is activated at high temperatures and increases stability of olive oil. Therefore, the virgin olive oil regarding to its nutritional properties, being rich in oleic acid (67%) and containing natural antioxidant compounds might be a good choice to be in the basket of goods of families for domestic frying.

Replacement with the cheaper animal fats or vegetable oils is conventional in milk through direct incorporation or homogenization of skimmed milk with less expensive foreign fats. The main objective of the present study was to evaluate the capability of a simple, fast, and reliable method for the detection of added palm oil in butter. The butter samples were mixed with palm oil (0.5-50 wt%) followed by gas chromatography analysis of fatty acids and sterols. The results confirmed the potential of discrimination based on a significant increase in the content of unsaturated fatty acids (C18:1 and C18:2) and a decrease in saturated fatty acids (mainly C10:0, C12:0, and C14:0). The differences are detectable for at least 10.0 wt% of the palm oil. Also, significant variations were observed in the cholesterol and sitosterol as marker sterols in the butter and palm oil, respectively. The study demonstrates the high potential of the procedure to rapidly detect and discriminate between butter-palm oil blends among pure samples.

The aim of this study was to produce the ice cream with potential antidiabetic effects by addition of pistachio peel extract (PPE) (0, 10, 20 and 30% on dry matter basis). The properties of produced ice creams such as physicochemical, rheological, antioxidant, antidiabetic and sensory properties were evaluated. The results indicated that ice creams containing 20 and 30% of PPE provided desired antidiabetic properties (the α-glucosidase inhibition was 79 and 86%, respectively). The DPPH• test results indicated that the antioxidant property of the ice creams containing 30% of PPE was 9.4 times more than the control. All mixes showed non-Newtonian pseudoplastic behavior and by increasing the concentration of PPE, the consistency coefficient (m) and viscosity were decreased. Hardness increased as the level of PPE increased but the stickiness decreased. Results of sensory analysis showed that the addition of PPE (up to 20%) had no significant effect on the overall acceptability of product.

In this study, the effect of basil seed gum (BSG) on the stability and rheological properties of egg white albumin (EWA) emulsions was investigated. A constant amount of EWA (0.5% w/v) and different concentrations of BSG (0-0.3% w/v) were used for the manufacture and stabilization of oil-in-water emulsions (30% w/w). The results showed that by increasing BSG concentration, the storage (21 days) stability of the emulsions was significantly (p < 0.05) improved. The highest creaming index was obtained in the case of the control emulsion (containing no BSG). Negative zeta potential was observed for all emulsion samples, with the emulsion containing 0.3% BSG showing the most negative surface charge, indicating the improvement in the stability of the manufactured emulsions in the presence of BSG. All of the emulsions showed shear-thinning flow behavior. The apparent viscosity increased with the increase in BSG concentration. Hysteresis area increased due to the increase in BSG concentration. The results of the frequency sweep test showed that storage and loss moduli increased by increasing the frequency and both of these moduli increased due to the increase in BSG concentration. Fitting frequency sweep data with power-law model confirmed a gel-like behavior for the emulsions containing a higher concentration of BSG. Overall, the findings of this study demonstrated that basil seed gum at an optimum concentration (0.3%) could be used as a natural stabilizer in the food emulsions containing egg albumin.

Poultry meat is a susceptible product for growth of spoilage and pathogenic microorganisms. The shelf life extension of raw poultry meat is a challenge in food industry. In this research, the combined effect of dipping in a carboxymethyl cellulose (CMC) solution containing black pepper seed (Piper Nigrum) extract (BPE) and turmeric (Curcuma Longa L.) extract (TE) (2% w/w) and vacuum packaging (VP) on shelf life extension of refrigerated chicken breast fillets was investigated. The parameters that were studied were microbiological (total aerobic mesophilic bacteria (TAMB) and total aerobic psycrotrophic bacteria (TAPB)), chemical (FFA, PV, TBARS and TVB-N) and sensory (odor, appearance and total acceptability) attributes. The coating containing TE showed a strong antimicrobial activity against TAMB and TAPB, but the effect increased synergistically in the presence of VP. The lowest FFA, PV and TBARS levels found in the vacuum packaged fillets coated with 2% TE in CMC solution. Color and appearance, odor and overall acceptability of VP-CMC-TE sample were the best during storage. Generally, the TE was more effective than BPE in extending the durability of chicken breast fillets.

Curcumin is a bioactive compound from turmeric which has different biological properties and health benefits such as antioxidant, anti-inflammatory, antimicrobial, and anticancer activities. However, the low solubility, poor bioavailability, and rapid degradation under neutral or alkaline pH conditions or when exposed to light, limit the food applications of curcumin. These problems can be solved by different strategies such as encapsulation. Therefore, different methods such as nanocomplexation, gelation, electro-spraying, complex coacervation, and pH-shifting approach have been applied to improve the solubility, stability, and bioavailability of curcumin. Consequently, the pharmacokinetic properties of curcumin including biological half-life and bioavailability/bio-accessibility can be improved resulting in better clinical and functional efficacy in vivo. Although the potentials of encapsulated forms of curcumin have been extensively studied in the literature, future studies can help to find better methods for developing encapsulation methods for curcumin for commercial and industrial aims. Accordingly, the present study was prepared to review the biological properties of curcumin. After that, the most common methods for the encapsulation of curcumin were also investigated.