Journal of Food Biosciences and Technology
Volume:7 Issue: 1, Winter-Spring 2017

The potential of quince powder was evaluated for the production of fiber rich sponge cakes. In this study, quinces slices were dried in an infrared–hot air dryer (375 W, 60°C and 1 m/s flow rate). The rheological properties of cake batters and physico-chemical, textural and sensory properties of the sponge cake supplemented with five different concentrations (control, 5, 10, 15 and 20 %) of quince powder were evaluated. The physical (volume, density, color) and chemical (moisture, protein, fat, carbohydrate and ash) attributes of the cakes were determined. The apparent viscosities of cake batters were increased from 11.47 to 33.63 Pa.s by increasing quince powder levels from 0 to 20 % (shear rate = 45.6 s-1). Increasing the level of substitution of quince powder from 0 to 20 % decreased the volume of cakes from 66.67 to 56.91 cm3. The density, consistency and hardness values of baked cakes increased with increasing quince powder levels from 0 to 15 %, whereas the volume, cohesiveness, resilience, chewiness and crumb L values of the samples showed a reverse trend. The results of sensory evaluation indicated that the cake with 10 % quince powder was rated the most acceptable.

The antioxidant activities of TBHQ, BHT and tocopherol mixtures at different concentrations (0, 100, 200, 400 mg/kg) have been evaluated by the application of Differential Scanning Calorimetry (DSC) and Rancimat apparatus. Rancimat apparatus that measures the secondary oxidation products was set at 110 ⁰C with an air flow of 18-20 L/h to measure the induction period (IP) of the samples. The DSC method was concerned with the oxidation of the samples in an oxygen flow DSC cell, while the cell temperature was set at isothermal temperature of 150⁰C. Oxidative induction time (T0), and the maximum of the peak (Tmax) were improved with increasing antioxidant concentrations. According to the results, tocopherols mixture was the most efficient antioxidant, followed by TBHQ and BHT. Furthermore, it was indicated that there is a good agreement (P<0.0001) between both methods and values obtained. In conclusion, the DSC method is a fast, convenient and reliable method to predict the antioxidant activities.

Milk-based espresso coffee is one of the most popular beverages. Foam is an essential quality characteristic for this beverage. Foam formation and stability is mainly related to the milk composition. In this study the influence of three different concentrations of Xanthan gum (0.05, 0.1 and 0.2 g dm-3) and three different temperatures (50, 60 and 70 °C) on foam stability were examined and experimental data was determined 5, 10 and 15 minutes after aeration. Sensory properties were also evaluated and the results were analyzed using Duncan’s mean comparison test at the probability level of 95%. The viscosity of coffee milk was increased due to the addition of Xanthan. The highest foam stability and sensory acceptance were observed in the product containing 0.2 g dm-3 Xanthan at 70°C.

Oxidative and microbiological degradations are the main factors that determine the quality of food and the shelf life. Color and moisture stability are important quality attributes that contribute to meat shelf life, salability and consumer acceptability. There is currently considerable interest in edible films coatings and natural antioxidants because of their potential to improve the quality and the shelf life. The objective of the present study was to investigate the effect of collagen fiber –based edible coating and green tea extract on physico chemical degradation in beef sausage stored at 4°C for two weeks in anaerobic packaging. Collagenbased edible coating with green tea extract (0.5 and 1% v/v) was used to reduce the oxidative degradation of sausages during two weeks of storage at 4 ͦC. Collagen fiber edible coating delayed the lipid oxidation of sausages as measured by the formation of TBARS. The moisture loss of sausages was significantly reduced by 46% with 1% tea extract coated-sausages as compared to the controls. Also, collagen and green tea extract coated-sausages were effective in maintaining the initial color of the samples.

The effects of dough fortification with different amounts of gluten and full fat soya flour on the quality of spaghetti were investigated. Rheological properties of dough, quality and sensory characteristics of spaghetti with different amounts of gluten (8 to 14%) and full fat soya flour (0 to 20%) were evaluated. Fortification caused improvement in some characteristics such as dough stability time and loosening degree and also had a negative effect on water absorption and dry spaghetti firmness. Some characteristics such as cooking loss, stickiness, cooking time and sensory features were improved with the addition of gluten while full fat soya flour showed negative effects. Dough development time was improved with more full fat soya flour contents while gluten showed unexpected effects. The optimal dough (12% gluten and 5% full fat soya flour) had improved stability time (68.5%), loosening degree (23%), cooking loss (30.61%), stickiness (15.79%), cooking time (23%) and sensory features (4.6%) as compared to the unfortified spaghetti. It was concluded that fortified dough is not recommended for short spaghetti products due to the higher dough development time than unfortified dough.

In this study, antimicrobial activity of chitosan and whey protein isolate edible films incorporated with different concentrations of zataria multiflora Boiss essential oil ;ZEO (1%, 2%, 3% and 4% v/v) and zataria multiflora Boiss essential oil nanoliposome (0, 1, 2, 3 and 4%) against  Listeria monocytogenes (ATCC 19118), Bacillus cereus (ATCC 11778), Staphylococcus aureus (ATCC 65138), Escherichia coli O157:H7(ATCC 35218) and vibrio parahaemolyticus (ATCC 43996) were evaluated using disc-diffusion test. The circular disks containing ZEO and NZEO were cut and placed on bacterial lawn. Plates were incubated for 24 h at 35° C. The inhibition zone diameter was measured by digital caliper. These inhibition zones were formed against Listeria monocytogenes (ATCC 19118), Bacillus cereus (ATCC 11778), Staphylococcus aureus (ATCC 65138), Escherichia coli O157:H7(ATCC 35218) and vibrio parahaemolyticus (ATCC 43996). The results of this study indicated that by increasing the concentration of ZEO in both whey protein isolate and chitosan films, a significant increase was observed in inhibition zones’ diameters (P<0.05). The greatest antimicrobial effect was achieved at 4 % concentration of essential oil against Listeria monocytogenes in both films. Whereas films containing NZEO did not show any significant antimicrobial activities at the highest concentrations. According to the results of the GC/MS analysis, Zataria multiflora Boiss. essential oil is a rich source of different antimicrobial compounds especially thymol and carvacrol which might be considered as the main reasons of the observed antimicrobial activities in the formulated biofilms. The results of this study indicated that whey protein isolate and chitosan edible films containing Zataria multiflora Boiss essential oil showed a good antimicrobial effect and this may be considered as an advantage to use them as an active packaging ingredient in food products.

Milk proteins provide a natural source of bioactive peptides with potential health benefits and applications in the food industry. The release of these peptides from milk proteins is achieved either by hydrolysis using digestive proteases or by lactic acid bacteria fermentation. Peptides, particularly those derived from milk proteins, can exert a wide range of nutritional, functional and biological activities. Bioactive peptides are inactive within the sequence of the parent protein molecule and can be liberated by gastrointestinal digestion of milk, fermentation of milk with proteolytic starter cultures or hydrolysis by proteolytic enzymes. They should be from 3 to 20 amino acids in size and many of them have multifunctional properties. Bioactive peptides have been isolated from several dairy products including cheese, kefir, milk, and yoghurt. Milk-derived peptides with antimicrobial activity have huge industrial potential, as they have the advantage of being derived from a safe and economical source. The aim of this review study is to introduce bioactive peptides with antimicrobial activities that have been produced from milk proteins.

Stevia rebaudiana Bertoni, is an ancient perennial shrub of South America, with great potential as a crop for the production of high-power natural sweetener. Due to its chemical composition and content of the phytochemical compounds, it is suitable as a raw material for the extraction and production of functional foods. Diterpene glycosides component of low-calorie sweetener is approximately 300 times sweeter than sucrose. In this study, the antimicrobial properties of Stevia rebaudiana Bertoni extract on pathogenic and food spoiling bacteria were tested by the disk diffusion method. The effect of Stevia rebaudiana extract on gram-positive and gram-negative bacteria were examined and on Bacillus cereus, Lactobacillus Plantarum, Leuconostoc mesenteroides, Salmonella typhimurium and Salmonella enterica exhibited inhibitory and germicidal effect, but the effects on Listeria monocytogenes was lower than the rest of organisms. The Minimum Inhibitory Concentrations (MIC) and Minimum Bacterial Concentrations (MBC) of Stevia extract was 1250 and 100001250 mg /ml respectively. The results showed that Stevia extract can prevent the growth of food pathogens and spoilage bacteria. Therefor we can use it as a natural sweetener and preservative in food products.

In this study the bacterial growth inhibitory activity of peptide fragments produced from goat’s milk whey proteins by enzymatic hydrolysis using trypsin, ficin and a combination of both was investigated. Goat’s milk whey proteins were isolated and subjected to enzymatic hydrolysis and peptides were purified by ultrafiltration followed by reverse-phase high-performance liquid chromatography (RP-HPLC). Growth inhibitory activities of hydrolysates ranged from 4.67% to 87.46% for E.coli and 3.03% to 98.63% for B.cereus. Among all peptide fragments, permeate containing 3kDa peptides produced by trypsin showed maximum inhibition against Gram positive and Gram negativebac bacteria. This fraction was further purified by HPLC. Fourteen peptide fractions were collected and evaluated for their growth inhibitory activities. Two fractions showed the highest growth inhibitory activities with MIC50’s of 383±8 µg/ml and 492±10 µg/ml against E.coli and B.cereus, respectively. Taken together, the results of this study indicated that it is possible to produce novel antibacterial peptide by enzymatic hydrolysis of goat’s milk whey proteins which can potentially replace synthetic food preservatives in food industries.

Functionality of Marve seed gum (Salvia Macrosiphon Boiss) on rheological properties and staling of Baguette bread have been studied. Three different concentrations of 0.1 %, 0.5% and 1% (w/w, flour basis) were applied and this hydrocolloid affected the quality of the stored bread to some extent. The effects of Marve seed gum on the rheological properties of dough was also investigated instrumentally by using two different techniques (farinograph and extensigraph). The effects of hydrocolloid on physical properties of bread were established by measuring the texture, crust colour and volume of baguette bread after baking. Texture and crust colour of baguette were respectively evaluated instrumentally through a texture analyser (TA) test and Hunter-lab instrument. Hedonic and descriptive sensory test of texture (odor, flavour, appearance and overall acceptance), were also carried out. All of the evaluations on baguette bread, were applied, 1 day, 3 days and 5 days after baking. In addition, good sensory properties for visual appearance, aroma, flavor, crunchiness and overall acceptability were obtained with 0.1% addition. There isn't a significant difference (p<0.05) between the control and 0.1% addition in the colour of bread. Texture analyses have shown that the addition of 0.1% Marve seed gum can keep the bread texture more acceptable than other breads, the most differences in 5 days after baking and less in 1 day after baking between 0.1% addition and the blank. In general, it can be concluded that with the addition of 0.1% Marve seed gum to the formulation, more qualitative parameters have been improved.