مجله علوم و صنایع غذایی ایران
سال هشتم شماره 3 (پیاپی 32، پاییز 1390)

In this study tomato pomace and sugar beet pulp were first dried، milled and sieved and then were added to wheat flour at levels of 0، 1، 3، 5. 7 and 10 % (w/w، flour basis). Then the water absorption and the rheological properties of the dough were determined using a Brabender Farinograph. The samples containing 7% of either of the pulps were further de-colorized using H2O2. The results showed that with increasing the level of either of the pulps، water absorption of the flour increased significantly. Increasing the level of sugar beet pulp، dough development and stability times increased، while dough softening decreased. Addition of tomato pomace powder had reverse effects on farinograph parameters. De-colorization of either of the pulps increased water absorption، dough development and stability times and reduced dough softening. In general، it was found that addition of sugar beet pulp powder to the flour could increase dough stability، while addition of tomato pomace powder to the flour could soften the dough and reduce its stability.

Modifications in fat and fatty acid composition of silver carp that take place at each stage of canning process (Precooking and Sterilization) were evaluated. Results showed، precooking led to decrease total fat and increase conjugated dines. The amounts of free fatty acids and thiobarbituric acids had no changed during precooking but these compounds like conjugated dine were increased after sterilization. Steaming had no effect on the fatty acid composition of silver carp however after sterilization as a penetrate of filling media linoleic and linolenic acids to fish tissue، fish fatty acids composition changed. Simultaneous a lot of fish fatty acids penetrate to filling media. This investigation showed، in spite of changes occurred on lipid quality due to canning process، the final product had adequate quality for human consumption.

Vibrios are human pathogens that are widely distributed in the marine environments. Those organisms are frequently isolated from a variety of raw seafood’s. Consumption of raw or undercooked sea food contaminated with some of Vibrio species، may lead to development of acute gastroenteritis and clinical specimens. The present study aimed at determining the contamination of shrimps caught off the south coast of Iran. A total 120 samples of fresh shrimp collected from marine shrimps (Paeneus monodon) were tested for possible presence of Vibrio species by cultural and biochemical analysis. Vibrio spp. was detected in 26. 7% of the samples analyzed in this study. Among Vibrio isolates، Vibrio alginolyticus was the species most frequently detected (43. 6%)، followed by Vibrio parahaemolyticus (34. 4%)، Vibrio vulnificus (9%)، Vibrio cholera and Vibrio orientalis (6. 5%). The results confirmed the need for a specific shrimp inspection plan to detect the presence of Vibrio species in order to eliminate public health risks associated with shrimp consumption.

In this research the effect of bioemulsifier (emulsan) on the staling process and the quality of Barbari bread was investigated. The bioemulsifier from the Acinetobacter calcoaceticus was produced at 1/8 gr in each littre of calture. After the extraction and purification، 0/05،0/2،0/5،0/75 and 1% were added to Barbari bread formulation and were compared with the control bread. The hardness of bread were measured after 1st، 2nd and 3rd days of baking. The sensorial tests were conducted on breads after baking. In this study،the pleasant effect for delaying the staling process by using 0/5% of emulsan was achieved. The results of Instron test showed that the 0/5% of emulsan increased the stability of bread significantly،in a way that the average of the necessary power for cutting the samples reduced from 243/9 in the control sample to 225،206/5،186،180/6 and 154/5 in the samples with 0/05،0/2،0/75،1 and 0/5% bioemulsifier. During 3-days storage time of bread containing bioemulsifier on the 2nd and 3rd days after baking. As a result،bioemulsifier is effective in reduction of the staling on the2 nd and 3rd days after baking. The results of sensorial measurement over lapped with the achieved results of Instron. In addition to the results of the sensorial measurements،there has been a positive change.

In this study experiments were conducted to determine the effectiveness of oregano and nutmeg essential oils (Eos) on the growth and survival of Staphylococcus aureus in broth culture and in ready to use barbecued chicken. Samples were prepared with 1، 2، and 3 µl/g of oregano and nutmeg Eos. The test and control (without Eos) samples were inoculated with the bacteria to a final concentration of 7 log CFU/g and stored at 3، 8، and 20°C. Based on growth on Baird–Parker agar، bacteria was counted just before and at 24، 48، and 72h. In the broth culture system، the antibacterial activity of oregano (MIC=0. 62 µl/ml and MBC=0. 62 µl/ml) was superior than that of nutmeg (MIC=1. 25 µl/ml and MBC= 2. 5 µl/ml). In barbecued chicken، the log CFU/g of bacteria after up to 72 h of incubation was not decreased significantly by various combination of Eos and storage temperature when compared with control samples (without Eos). It is concluded that examination of Eos in broth system can yield accurate microbiological data، without complementary tests in foods these data are of limited value for assessing food safety.

In this study، antimicrobial effects of the carboxymethyl celloluse (CMC) based-edible films containing 1-4% potassium sorbate (as a antimicrobial agent)، were tested against Aspergillus flavus (PTCC 5004)، Aspergillus parasiticus (PTCC 5286) and Aspergillus parasiticus (PTCC 5018) by using agar diffusion assay. The films containing 1 and 2 % potassium sorbate showed the inhibitory zone against first and second molds however، they were not effective against Aspergillus parasiticus (PTCC 5018) at these levels of antimicrobial compound. Maximum inhibition zone was observed in 3 and 4% potassium sorbate for all molds. Fresh pistachios were purchased from local market and immersed in aqueous filmogenic solutions of CMC with different concentrations of sorbate (0. 25، 0. 5 and 1%). In uncoated pistachios، molds counting، showed 2. 02×106 CFUg-1 while in the coated samples there was no growth of any molds.

The influence of adding soy flour in five levels (25، 35، 45، 55 & 65%) and the amount of gluten in four levels (1، 3، 5 &7%) on the characteristics of sensory and cooking quality and chemical contents of spaghetti was investigated. Results in completely randomized design with factorial design with two factors the amount of soy flour and gluten in the amount of four repeats for each test were analyzed and the difference between the means by Duncan test at 95% confidence level was calculated. The results showed that adding gluten and soy flour in formulation increased significantly (P≤0. 05) protein، fat and ash of spaghetti samples. Regarding the characteristics of cooking of spaghetti، revealed that soy flour reduced significantly)P≤0. 05) cooking time، increasing loss after optimum and over cooking time، and decreased weight after optimum and over cooking time. However، adding gluten improved significantly (P≤0. 05) the cooking properties of spaghetti. Sensory evaluation results showed that with increasing amount of soy flour in the formulation، overall acceptance of samples decreased. Generally، in samples with 7% gluten and 25% soy flour، amount of protein and cooking weight was highest، and the cooking loss was lowest than the other samples.

In this study، some physical properties of Jahromi lime fruits were investigated. Physical properties such as mass، main diameters، volume، density، sphericity and geometric mean diameter were measured. Material testing machine was used to measure mechanical strength by using two plates compression test. The experiments were carried out at three mass levels (m>23 g، 18 g < m <23 g، m< 18 g)، three loading speeds (100، 200 and 300 mm/min) and two loading directions [vertical (in maximum diameter direction) and horizontal (in medium diameter direction)]. Strength properties such as failure force and energy، toughness and elasticity module were determined. Result of physical properties of limes showed that the averages of mass، volume، density، sphericity and geometric mean diameter were 21. 48 ± 5. 98 g، 21. 24 ± 6. 00 cm3، 1. 012 ± 0. 008 g/cm3، 0. 90 ± 0. 04 and 34. 07 ± 3. 27 cm، respectively. Also، results showed that loading direction، loading speed and size factors had significant effect on elasticity module (p< 0. 01). Interaction effect of loading speed and the size had significant effect on the failure energy (p< 0. 01) and toughness (p< 0. 05). But none of them have significant effect on the failure force. Moreover، the result showed that the loading speeds have indirect relation with failure energy and direct relation with toughness and elasticity module. Therefore، size had no effect on failure energy and toughness but size and elasticity module had indirect relation.

The post-harvest physical and mechanical properties data of fruits and vegetables are important in adoption and design of various handling، packaging، storage and transportation systems. In this research some of physical and mechanical properties of two varieties of almond kernel were investigated. The mean values of geometrical properties including; length، width، thickness، the geometric mean diameter، weight، volume and sphericity for Azar variety were 21. 01، 11. 53، 5. 31، 10. 91 mm، 0. 695 gr، 673. 1 mm3 and 52. 02% and for Nonpareil were 19. 54، 10. 96، 5. 24، 10. 38 mm، 0. 570 gr، 547. 9 mm3 and 53. 27%، respectively. Also، properties such as; particle density and bulk density، frictional properties of Almond kernel on the plain steel، galvanized steel and aluminum for the two varieties of Almond، that is، Azar and Nonpareil were measured. At present research، also by cutting loading tests، some of mechanical properties of almond kernel such as force، energy and power requirement for cutting of kernel were investigated. The tests were carried in three size levels (small، medium and large) and three loading speed (5، 50 and 100 mm/min) and three moisture levels (5، 15 and 25%) with 10 replication. The effect of three factors; size، speed، moisture and their multiple effects were measured for both varieties. Finally، the mean values of mechanical properties both varieties were compared. The mean force، energy and power requirement to cutting of kernel for Azar variety were 15. 43N، 6. 12mJ، 0. 0058W and for Nonpareil were 17. 03N، 8. 19 mJ، 0. 0071W، respectively.

Alicyclobacillus acidoterrestris has recently obtained great attention in fruit juice industry due to its high resistance to juice pasteurization. Several methods for inhibition of this bacterium have been proposed. Pomegranate peel، as a byproduct of fruit juice factories، has antibacterial and functional properties. Pomegranate peel extracts containing effective compounds were extracted by methanol (MeOH)، ethanol (EtOH) and acetone. In comparison within different extracts، pomegranate peel extracted by acetone (PPEA) had the highest content of phenolic، flavonoid and flavonol contents، (i. e. 226، 70 and 61 mg/g، respectively). Furthermore، 250μg/ml PPEA showed strong anti-Alicyclobacillus acidoterrestris property on orange serum agar and apple juice without any side effects on apple juice turbidity. The extracts obtained by EtOH and acetone during 24 days showed side effects on apple juice turbidity in 1000 μg/ml but the extracts obtained by MeOH did not affect apple juice turbidity at the same time.

In this study، the effect of using palm and corn oils as a partial or whole Substitution of milk fat (0، 33، 50، 66، and 100%) on the physical and chemical properties of pizza processed cheese was investigated. No significant effect was found on the meltability and strechability of pizza cheese made by different oil sources، whereas، oiling off، iodine number as well as saponification number were significantly affected by the type of oil used in the formulation of pizza cheese (p<0. 05). The high correlation (-0. 717) between the oiling off and saponification number enable us to use the later as a diagnostic element to distinguish pizza cheeses made by vegetable oil sources as a replacement of milk fat which is illegal in some countries as well as Iran.

Non-alcoholic beer (Ma-al-Shaeer) is a commonly consumed and popular beverage in Islamic countries. Its popularity originates not only from the pleasurable sensory attributes and relatively low cost، but also from its health beneficial effects when consumed in moderate amounts. Qualitative aspects of non-alcoholic beer from the consumer point of view، which is so-called here as “functional qualitative aspects” (flavor، color، foaming property، body، viscosity and mouthfeel، colloidal stability، nutritional and medicinal aspects as well as hygiene) play a crucial role in its acceptability. This article reviews these qualitative aspects، in physical and chemical categories.