فصلنامه پژوهش و نوآوری در علوم و صنایع غذایی
سال چهارم شماره 3 (پاییز 1394)

Acrylamide is a chemical compound which starchy foods such as biscuits are prone to formation. Since biscuit is one of the most consumed floury products specially for children، the objective of this research is to assay the effect of the replacement of whey protein powder with dried milk in the 3 levels (25، 75 and 100 %)، and the effect of the replacement of ammonium hydrogen carbonate and baking powder with sodium hydrogen carbonate on acrylamide، reducing sugar، protein، moisture، pH and acidity content on Petit Beurre and Madar biscuits were investigated. By increasing whey protein powder replacement in both kinds of biscuits، pH، only in samples which were completely produced by dried milk powder and whey protein powder، was considerable. In this phase protein content had decreasing، while acidity and reducing sugar had increasing procedure. The content of acrylamide in Madar and Petit Beurre biscuit samples produced by 100 % whey protein powder، in comparison with control، decreased 11. 9 % and 4. 1 % respectively، which may be related to the decrease of protein content in formulation. The content of pH and acidity respectively decreased and increased by replacing sodium hydrogen carbonate with baking powder. By using sodium hydrogen carbonate in both biscuit samples the content of reducing sugar considerably decreased. The minimum and maximum amount of acrylamide was observed in the samples containing sodium hydrogen carbonate and ammonium hydrogen carbonate، respectively.

The purpose of this study was to compare two clean-up methods i.e. immunoafinity and multifunctional (MycoSep) columns in determining aflatoxins (B1, B2, G1 and G2) in black, white and red pepper samples with high performance liquid chromatography (HPLC). Blank samples of black, white and red pepper were spiked with 1, 5 and 10 ng/g of the toxins. The spiked samples were cleaned up by applying MycoSep and immunoaffinity and recovery values were determined. Preparing six samples of pepper from the market, aflatoxins were measured by both of the clean-up methods in each of the afore mentioned samples. Data were analysed by analysis of variances. When the immuniaffinity column was applied, the recovery values ranged from 69.8±6.6 for G2 to 101.5±5.7 for B1. By applying mycocep column the recovery was ranging from 70.9±3.4 for G2 to 97±8.8 for B1. Data analysis showed that there were no significant differences between recovery values and mycotoxn content in real samples applying immunoaffinity or mycocep. Both methods were found effective.

Pepper oleoresin is dense oil and/ or semi-solid extract that is used as a flavoring and coloring agent in various food products. Spicy taste of red pepper oleoresin is due to a group of alkaloids called capsaicinoids. In this study for the first step, red pepper oleoresin was extracted using ethanol, methanol and 2-propanol as extraction solvents. In the second step, extracted capsaicinoids were encapsulated with Arabic gum and whey protein concentrate (WPC) as ingredient wall material applying spray drying method. The statistical results showed the type of solvent had a significant effect on the efficiency of the extraction, while for the ratio of powder to solvent no significant differences in the efficiency of extraction was observed. The effect of composition of wall material (5, 10 and 15 %) and blending ratio polymeric matrix of gum Arabic and WPC (in the ratio of 100:0, 1: 1, and 0:100) on the size of the powder containing encapsulated capsaicinoids as well as encapsulated efficiency were evaluated. It was observed that the composition of wall material and blending ratio of polymeric matrix affected the mean diameter, particle size distribution, and specific surface area. That is to say, the retention time of active ingredients in gum Arabic was more than WPC. In addition, the encapsulation efficiency and remaining of capsaicinoids in the capsule increased as the wall material concentration increased from 5 to 15 percentages.

The aim of this study was the production of mozzarella cheese flavored with thymus vulgaris essence and the examination of the inhibitory effect of this essence against mold, yeasts, E.coli and coliforms, some proteolitic and lipolytic reaction and shelf life of mozzarella cheese in refrigerator conditions. In this study, the effect of different percents of essence (zero, 0.001, 0.003, 0.005) was investigated on physicochemical, microbial, antioxidant and organoleptic properties of mozzarella cheese at refrigerator temperatures for 45 days.The results showed that zero, 0.003 and 0.005 concentration had a significant effect on reduction of coliforms, E.coli, molds and yeasts growth(P<0.05). Also, 0.003 and 0.005 percent of the essence, had a significant effect on reduction of peroxid index during shelf life (P<0.05) and had no significant effects on pH, acidity, moisture and salt content)P>0.05(.Also, samples with 0.005 % essence had the most flavor and overall acceptance. Generally the results showed that thymus vulgaris essence as a natural preservative is able to increase the shelf life of mozzarella cheese at refrigerator temperature.

Native inulin extracted from chicory root consists of chains of fructose units by β (2→1) bonds with different degrees of polymerization. Inulin composition and its functional properties depends on genetic characteristics, growth environmental conditions, harvesting time, as well as the method of extraction the processes applied after extraction. "Short-chain" inulin, is more soluble and sweeter, so it can be used as sugar replacer, while "long-chain" inulin, commonly used as a fat substitute, is less soluble, more viscous and thermally stable. In this research, for isolating different structural fractions of inulin, root of chicory strain of Orchies was used. The Effect of different treatments including ethanol solvent to syrup ratio (2:1 and 10:1), crystallization and precipitation of aqueous solution in -20°C, and ultrafiltration using 4 kilo-dalton UF cut off on the degree of polymerization, yield of extraction and physicochemical properties of the compounds were compared. The results showed that ethanol with higher concentration resulted in more precipitation of inulin. Inulin participated by 2:1 E/S ratio had the highest degree of polymerization (66) and the least reduced sugar (1.2%) compared to those from other methods of fractionation. Inulin participated by ultrafiltration of permeate fraction had the lowest degree of polymerization (16) and highest reduced sugar (5.31%) compared to those from other methods of fractionation.

Microwave dry-diffusion and gravity extraction (MDG) is an advanced microwave-assisted extraction technique. The aim of this study, was a comparison of different extraction methods namely MDG, microwave-assisted hydrodistillation (MAHD), and hydrodistillation (HD) methods and also evaluation of their effectiveness in isolation of essential oils from fresh Rosmarinus officinalis leaves. Variables such as extraction yield, extraction time, chemical composition, antioxidant activity, and operation cost were compared. The obtained results showed that the extraction times of essential oil by MDG, MAHD, and HD were 5, 15, and 120 min, respectively and energy consumptions were 0.04, 0.13, and 1.00 kW h, respectively. MDG offered important advantages over traditional HD method, namely increasing antioxidant activity (10.3%) and providing a more valuable essential oil components (α-pinene 17%, camphene 2.1%, and 1,8-cineole 2.8 % more than HD method). Gas chromatography/mass spectrometry analysis of the extracted essential oils indicated that microwave did not adversely influence the composition of the essential oils. In comparison with HD and MAHD, MDG required less energy, cost, and solvent. Hence, MDG can be proposed as a green and novel extraction technology.

In this study, protein hydrolysate was prepared from whey protein concentrate with Alcalase 2.4 L. The effects of temperature (40, 45, 50 and 55 °C), time (30, 60, 90, 120, 150, 180 and 210 min) and enzyme/substrate ratio (30, 60 and 90 Anson unit), on antioxidant activity of the product were investigated in a completely randomized design. The antioxidant activity of protein hydrolysate was studied using reducing power and Fe2+ chelating activity. The highest Fe2+ chelating activity (87.2%) was observed in temperature 50 ºC, enzyme activity of 60 Au/kg and hydrolysis time of 90 min. The highest reducing power (0.435) of protein hydrolysate was observed in temperature of 40ºC, enzyme activity of 90 Au/kg and hydrolysis time of 210 min which showed 57.08% reducing power compared to 100 ppm ascorbic acid. The results indicate that the antioxidant peptides can be used as a natural antioxidant in food formulations, as well as a pharmaceutical composition.