فهرست مطالب

Nutrition and Food Sciences Research - Volume:3 Issue: 4, 2016
  • Volume:3 Issue: 4, 2016
  • تاریخ انتشار: 1395/08/18
  • تعداد عناوین: 8
|
  • Azizollaan Zargaraan, Leila Kamaliroosta, Amin Seyed Yaghoubi, Leila Mirmoghtadaie Pages 3-11
    High fructose corn syrup (HFCS) is commonly found in soft drinks and juice beverages, as well as in many pre-packaged foods such as breakfast cereals, baked goods and dairy desserts. Historically, sucrose (table sugar) was primarily added to processed foods and beverages as the sweetening agent. In recent years, the use of HFCS has significantly increased in popularity due to its sweetness, ability to enhance flavor and shelf life, and its low cost. HFCF made by enzymatic isomerization of glucose to fructose was introduced as HFCS-42 (42% fructose) and HFCS-55 (55% fructose) and opened a new frontier for the sweetener and soft drink industries. Using a glucose isomerase, the starch in corn can be efficiently converted into glucose and then to various amounts of fructose. Hydrolysis of sucrose produces a 50:50 molar mixture of fructose and glucose. The primary difference is that these monosaccharides exist free in solution in HFCS, but in sucrose bonded together. The disaccharide sucrose is easily cleaved in the small intestine, so free fructose and glucose are absorbed from both sucrose and HFCS. The advantage to food manufacturers is that the free monosaccharide in HFCS provides better flavor enhancement, stability, freshness, texture, color, pourability, and consistency in foods in comparison to sucrose. The development of these inexpensive, sweet corn-based syrups made it profitable to replace sucrose (sugar) and simple sugars with HFCS in our diet. In the present study, the replacement of sucrose with HFCS and its effect on the functionality and organoleptic properties of different food products were reviewed.
    Keywords: High fructose corn syrup, Bakery products, Dairy products
  • Veda Vakili, Majid Khadem, Rezaiyan Pages 13-21
    Background And Objectives
    Low Fruit/Vegetable (FV) diet seems to be a global public health problem. The trans-theoretical stages of change model have long been considered a useful interventional approach in lifestyle modification programs. The aim of this study was to find the most important intermediating factors of FV consumption in Mashhad, Iran.
    Materials And Methods
    In this cross-sectional design, 777 participants were included with a convenient method from the general population in public places all around the Mashhad City, Iran in 2014. A standardized checklist about socio-demographic characteristics and possible related factors and stages of change questionnaire (6 stages: pre-contemplation, contemplation, preparing, action, maintenance, and termination) were used for data collection. Data were analyzed by SPSS 11.5 software using Chi-square test, Mann-Whitney U test, and Multiple Logistic Regression.
    Results
    Totally, 254 (47.7%) and 299 (59.8%) of participants were in pre-action stages of FV, respectively. Smoking (OR=3.2, p=0.02) and believing that this is good for the body (OR=0.12, p=0.001) were predictors of the pre-contemplation stage for fruits. Being physically active (OR=2, p=0.008), low agreement with health benefits of vegetables (OR=8, p
    Conclusions
    Understanding the pros and cons of changing lifestyle can help public health specialists to perform targeted interventions.
    Keywords: Behavior, Fruit, Vegetable, Trans, Theoretical Model, Urban population
  • Fatemeh Esmaeili Shahmirzadi, Arash Rashidi, Saeid Ghavamzadeh Pages 23-28
    Background And Objectives
    Several studies have so far been carried out to determine the prevalence of overweight and obesity among Iranian children but few studies have investigated the relationship between eating habits, socio-demographic differentials and obesity in these children. So, this study tried to assess the body weight status among the urban high school boy students of Urmia, Iran.
    Materials And Methods
    In this cross-sectional study, we measured weight, height and BMI of 1026 boy students with an age range of 15 to 19 years by multi-stage sampling. Then a questionnaire was completed based on their dietary habits and behaviors related to their physical activity. Overweight and obesity were defined based upon the World Health Organization’s growth charts. Statistical analysis was fulfilled by estimating absolute and relative frequencies.
    Results
    Underweight prevalence in the studied population was 9.84% (95% CI: 8.49%-10.72%). The prevalence of overweight and obesity among the studied students was 12.77% (95% CI: 11.89%-13.3%), and 5.07% (95% CI: 4.5%-5.9%), respectively. Factors significantly correlated with the participant's body weight were the frequency of energy dense foods intake during a week (P
    Conclusions
    In the present study, we found that two changeable parameters (i.e. the number of times for intake of energy dense foods during a week, and working with computers) could influence the 15-19 years old school boy's body weight in the study region.
    Keywords: Prevalence, Underweight, Overweight, Obesity, High school boys
  • Sedighe Tavasoli Talarposhti, Mohsen Barzegar*, Zohreh Hamidi, Esfahani Pages 29-40
    Background And Objectives

    Edible parts of pomegranate fruits are a rich source of bioactive compounds. The present research examines the effect of modified atmosphere packaging on the fruit physico-chemical and microbial properties of two commercial pomegranate cultivars grown in Iran.

    Materials And Methods

    The arils were packaged and stored under four different atmospheres. All of the packaged samples were stored at 4 °C for 15 days.

    Results

    The results revealed an increase in total acidity of all treatments. The highest total soluble solid (TSS) was observed in ‘Yousef-Khani’­ stored in 10% O2 15% CO2, while ‘Malas-e-Saveh’ treated with 20% O2 5% CO2 showed the highest degree of TSS. The mean value of a* in ‘Malas-e-Saveh’ arils packed with normal and (15% O2 10% CO2 75% N2) atmosphere increased significantly. The L* showed a decrease in ‘Yousef-Khani’­. Total phenolic compounds gradually increased during storage. After storage, decreases in total anthocyanin contents ranged from 12 to 30% for ‘Yousef-Khani’­. The overall antioxidant activity of arils in ‘Yousef-Khani’ showed a 6-15% increase during storage. However, a reverse effect was observed for ‘Malas-e-Saveh’. The lowest microbial counts were recorded under the atmosphere containing 10 and 15% CO2.

    Conclusions

    Packaging of ‘Malas-e-Saveh’ arils in 15% O2 10% CO2 and ‘Yousef-Khani’ in 15% O2 10% CO2 or 10% O2 15% CO2 is recommended to extend the shelf-life of ready-to-eat arils.

    Keywords: Pomegranate, Modified atmosphere, Phenolic compounds, Anthocyanin, Antioxidant activity
  • Reza Sharifanfar, Hossein Mirsaeedghazi, Ali Fadavi, Mohammad Hossein Kianmehr Pages 41-48
    Background And Objectives
    Pomegranate juice (PJ) contains large particles that stick to evaporator walls causing off flavors in the concentrate due to burning. Microfiltration is used to clarify PJ. Fouling is a limiting phenomenon that can prevent the industrialization of membrane clarification. Changes in the geometry of the membrane module such as using baffles are useful to decrease this problem. Computational fluid dynamics (CFD) is a powerful numerical tool used in modeling membrane processing.
    Materials And Methods
    The effect of baffle geometry on the efficiency of membrane clarification of pomegranate juice in a flat-sheet module was simulated using computational fluid dynamics (CFD). The geometry of the membrane unit was plotted and meshed with Gambit software, and was solved using FLUENT software. A two-dimensional double-precision method at steady state was selected to simulate the membrane process. The convective terms were discretized with a standard first-order upwind scheme in computational solution. The RNG k- model was used due to its high accuracy in eddy flows with a low Reynolds number. The effects on the process performance of the number of baffles, their angle and the distance between the baffles and the membrane surface were evaluated.
    Results
    The results showed that the configuration with the feed-channel height of 2 cm, the baffle angle of 90o and the distance between the membrane surface and baffles of 2 mm had maximum permeate flux.
    Conclusions
    Reducing the distance between the baffles and the membrane surface increased the permeate flux due to create an eddy flow near the membrane surface in the flat-sheet module and reduced the total and cake-layer resistances.
    Keywords: Baffle, Computational fluid dynamics, Juice, Membrane, Pomegranate
  • Mohammad Faraji, Mahnaz Adeli Pages 49-56
    Background And Objectives
    The addition of plasticizers (mainly phthalates and adipates) makes plastic flexible and popular for packaging, storing and preserving food, water, and so on. The most widely used plasticizer in food contact applications is di-ethylhexyl phthalate (DEHP) though being suspected to have carcinogenic and estrogenic properties. The aim of this study is application of magnetic solid phase extraction as new absorbent for determination of DEHP in water samples by gas chromatography (GC).
    Materials And Methods
    Important factors in extraction, separation and determination processes were optimized using the one-variable-at-a-time method. For optimization, all tests were performed two times. Figures of merit of the proposed method were evaluated. The amount of DEHP in some water samples was determined using the proposed method.
    Results
    The results showed that the obtained chromatogram of extract was free of significant interference. The preservatives’ recoveries ranged from 91.6% to 102.2%. Limit of detection and limit of quantitation were 0.1 mg kg-1 and 0.3 µg L-1, respectively. Concentration of DEHP in the studied samples was in the range of N.D-2.3 µg L-1.
    Conclusions
    The acceptable performance and reliability of the proposed method were demonstrated. Temperature and time were fount as the most effective parameters in migration of DEHP.
    Keywords: Di, ethylhexyl phthalate, Magnetic solid phase extraction, Migration, Gas chromatography
  • Haniyeh Moallem Bandani, Fardeen Ali Malayeri, Donya Arefi, Majid Rajabian, Reza Entezari Heravi, Miss Laleh Rafighdoost, Miss Saeedeh Sepehrikiya Pages 57-62
    Background And Objectives
    Heavy metals such as cadmium and lead are the most important toxins spreading through various ways like water, soil, and air in nature and easily enter human food chain. It is essential to determine the cumulative and harmful effects of these metals in nutrients, especially in cow milk because it is a unique source of food for all ages and it contains both essential and nonessential trace elements.
    Materials And Methods
    A total of 100 milk samples were directly collected from healthy cows in Zabol located on east of Iran. The samples were tested to determine lead and cadmium residues. The rates of the heavy metals were determined using a Rayleigh atomic absorption spectrum equipped with hollow cathode lamps (HCL) at 283.3 nm for lead (Pb) and at 228.8 nm for cadmium (Cd). By using the photo-catalytic titanium dioxide nanoparticles, these toxic metals were removed.
    Results
    The mean ± SD of the concentration of lead and cadmium in raw milk were 9.175± 2.5 and 4.557 ± 1.081 ppb, respectively. Also, the P-values of Kalmogorov– Smiranov test for lead and cadmium were respectively 0.057 ppb (P>0.05) and 0.435 ppb (P>0.05). TiO2 nanoparticles were used to eliminate and remove lead and cadmium in milk samples. The results showed that there was a significant difference between lead and cadmium contents before and after adding TiO2 nanoparticles (P
    Conclusions
    According to results of this study, there was a very low amount of toxic metals. So, it seems that it is not necessary to use TiO2 in milk samples but these days it used frequently as an additive to some samples like milk to remove these pollutants.
    Keywords: lead, cadmium, milk, atomic absorption spectroscopy, TiO2 nanoparticles