Current Nutrition & Food Science (v.13, #3)

Editorial : Meet Our Editorial Board Member by Mario J. Soares (155-155).

Numerous studies have shown that our often hectic lives and busy schedules can lead to unhealthy levels of stress and body fatigue while, simultaneously driving people to choose fast food as their main source of nutrition as well as being a comfort food. Such eating behaviour is a major risk factor for compromising health, especially the development of chronic health problems such as heart disease, diabetes, asthma, obesity and other medical conditions. This paper highlights the negative influence on eating habits and health of socio-technical developments in the fast food industry and the importance of reducing the resulting rise in chronic health problems in society.

Homocysteine in Neurology: From Endothelium to Neurodegeneration by Rita Moretti, Matteo Dal Ben, Silvia Gazzin, Claudio Tiribelli (163-175).
Vitamin B12 and folate are supplied via two major pathways, the conversion of homocysteine to methionine and the conversion of methyl malonyl coenzyme A to succinyl coenzyme A. Therefore, the defect in both the vitamins results in an increase in both serum homocysteine and methylmalonic acid. Hence, homocysteine, vitamin B12, and folate are closely linked together in the so-called one-carbon cycle, making vitamin B12 the necessary co-enzyme for the methyl donation from 5-methyl-tetra-hydrofolate in tetra-hydro-folate, necessary for methionine synthetase. Folate is a cofactor in one-carbon metabolism, and it promotes the remethylation of homocysteine, which can cause DNA strand breakage, oxidative stress and apoptosis. Vitamin B12 and folate are involved in nucleic acid synthesis and in the methylation reactions, and their deficit causes the inhibition of S-adenosylmethionine mediated methylation reactions, and through the related toxic effects of homocysteine, a possible direct alteration of the vascular endothelium and inhibition of N-methyl-D-Aspartate receptors take place. We discussed the possible and still controversial role of homocysteine accumulation in cerebral pathologies, starting from vascular events to neurodegeneration and to endothelium damage mechanism.

Background: Fermented bamboo shoot is commonly consumed as a traditional food among the North Eastern communities of India.
Objective: To scientifically validate the mechanism of traditional bamboo shoot fermentation using different additives.
Method: Bamboo shoots were fermented using different additives under laboratory conditions for 10 days and analyzed for change in pH, acidity, total bacterial count and Lactic Acid Bacteria (LAB) count.
Results: During fermentation the titratable acidity increased resulting in the decline in pH in all the samples except the one in which acetic acid was added. Microbiological analysis of the samples showed that the population was dominated by Lactic Acid Bacteria (LAB) and the count increased from 102 cfu/g to 105 cfu/g at the beginning of fermentation till the end. Thirteen strains were isolated out of which eight were confirmed to belong to the genus Lactobacillus. Based on the biochemical characterization it was confirmed that Lactobacillus genera dominates in all the samples of the fermented bamboo shoot.
Conclusion: Bamboo shoots fermented with the help of different additives aided in the fermentation process and act as flavor enhancers and thus can be recommended during fermentation to enhance taste and palatability.

Quality Assessment of Wheat Bread with Microbial Transglutaminase Supplemented with Hull-Less Barley Flour by Kiana Pourmohammadi, Seyed Mohammad Bagher Hashemi, Amin Mousavi Khaneghah, Roya Afshari, Mehran Alami, Mohammad Shahedi, Alireza Sadeghimahoonak (182-191).
Background: In the current study, the impact of MTG incorporation (0, 0.5%, 1%, 1.5% and 2%; W/W) into wheat flour supplemented with 20, 35 and 50% of hull-less barley flour on quality parameters of produced bread were investigated. Soy Protein Isolate (SPI) was used at a level of 3% (w/w) in order to increase the level of lysyl residues as well as extend the crosslinking of protein matrix.
Material and Methods: Prepared bread was evaluated in terms of loaf volume, color characteristics and firmness during baking.
Results: The addition of MTG on wheat proteins significantly decreased the loaf volume and extensibility of samples while the resistance and lightness of samples were increased. Incorporation of MTG at 0.5% would decrease the degree of softening and mixing tolerance index of flours.
Conclusion: The formulation of hull-less barley bread quality could be improved by incorporation of MTG.

Physicochemical, Functional and Biscuit Making Properties of Wheat Flour and Potato Flour Blends by Pinki Saini, Neelam Yadav, Devinder Kaur, V. K. Gupta, Bandana Kaundal, Pragya Mishra, Anjali Mishra, Rajendra Kumar (192-197).
Background: Potato flour, being nutritious and a high source of carbohydrates, has been explored for the manufacturing of biscuits.
Methods: Replacement of refined wheat flour with potato flour at various levels (5 to 30%) was done for the preparation of biscuit. The physicochemical and functional properties of wheat flour, potato flour prepared from Kufri Chipsona-1 and flour blends were also studied.
Results: The nutritional composition of potato flour indicated a higher fibre (3.50%) and carbohydrate (82.79%) content than wheat flour. Wheat flour showed higher water holding capacity (7.4 ml g-1), oil holding capacity (2.8 ml g-1), water retention capacity (50.4%) and alkaline water retention capacity (55.8%) than potato flour. The crude fibre and carbohydrate content of biscuits increased significantly (p<0.05) from 2.34 to 3.52% and 68.88 to 69.72%, respectively, after incorporation of potato flour. The spread ratio of biscuits decreased with incorporation of potato flour. The L* value decreased significantly (p<0.05) from 30.44 to 25.47 whereas the hardness of biscuits increased significantly (p<0.05) from 9.8 N to 20.8 N on increasing the level of potato flour incorporation.
Conclusion: The sensory characteristics of biscuits prepared by replacing wheat flour by 25% potato flour were similar to control sample. The functional properties also showed an increasing trend with increase in the incorporation of potato flour.

Background: Proteins are more satiating than fat and carbohydrate but in a sourcedependent manner. Whey Protein Isolate (WPI) and Glycomacropeptide (GMP) suppress Food Intake (FI) in both humans and animals. The objective of this study was to compare the effect of whey protein and GMP preloads on regulation of FI and blood glucose in male Wistar rats. In this study, Rats were allocated to five groups and received one of following in a cross-over design: 1) water; 2) WPI; 3) WPI+devazepide (CCK-1 receptor blocker); 4) GMP; and 5) GMP+devazepide. Food intake, plasma glucose, insulin, CCK and ghrelin were measured.
Results: Plasma CCK concentration was higher 30 min after administration of WPI and GMP compared with the water control. Devazepide increased FI when it was co-administered with WPI and GMP preloads at 1 hour compared with FI after administration of WPI or GMP alone. Ghrelin was lower after WPI administration compared with water control. No differences in glucose and insulin concentrations were observed.
Conclusion: CCK-1 receptors mediate FI suppression induced by both WPI and GMP. However, this effect is limited to the first hour of FI. No differences in the effect of WPI and GMP on glucose metabolism were observed.

Fermentation of Barberry Juice to Produce Probiotic Beverage by Seyed Mohammad Bagher Hashemi, Maryam Mahmoodi (204-211).
Background: The demand for nondairy fermented products has increased, and probiotic microorganisms have been incorporated into fruit juices.
Methods: The effects of fermentation by Lactobacillus plantarum PTCC 1058 on carbohydrates, organic acids, phenolic compounds, ascorbic acid, antibacterial and antioxidant activities as in the barberry well as the sensory aspects were investigated.
Results: The viable cells of L. plantarum with a consequent grow reached to 8.91 log CFU/mL after 48 which was higher than 7.00 Log CFU/mL throughout the storage time at 4 A°C within 28 days. Fructose and glucose were significantly consumed by L. plantarum as a probiotic starter. Although the concentration of citric acid was significantly reduced by L. plantarum through the process (p<0.05), the no significant change in concentration of formic acid, as the main acid of the juice was observed. Lactic acid was detected as acidic metabolite (7.5 g/L) of the fermentation. It should be notedthetotal phenolic compounds, anthocyanins, and ascorbic acid content were significantly decreased in barberry juice during fermentation and storage (p<0.05). Results indicated fermented juice had a good antibacterial activity against E. coli O157 H7 and Bacillus cereus. DPPH radical scavenging and FRAP studies showed the antioxidant activity of barberry juice was increased significantly by fermentation (p<0.05).
Conclusion: Fermentation of barberry juice by L. plantarum would enhance the health benefits of the juice as well as desired properties.

Physicochemical Properties, Microbial Quality and Sensory Attributes of Different Black Tea Brands by Kobra Keshavarz Faizasa, Mohammadreza Koushki, Shiva Roofigary Haghighat (212-218).
Background: There are different types of local and international tea brands in the Iranian market having variation in their composition and quality; however, to the best of our knowledge, no proper study has been reported in Iran in this regard so far. The present study was undertaken to determine the physicochemical properties, microbial quality and organoleptic attributes of tea.
Methods: This study was carried out with 500 g packages of three Iranian and four international black tea brands. The tea brands were then coded, and stored until further analysis according to Iranian and international standards.
Results: International tea brands had the highest amount of caffeine (3.67), total soluble solid (water extract) (40.48), water soluble ash (67.91), alkalinity of water soluble ash (1.70) and bulk density (285.6), and the lowest amount of crude fiber (11.83). The lowest percentage of moisture content was observed in Iranian tea brands (4.96). Scores given to the organoleptic characteristics of Iranian and foreign tea brands were 13.25-14.25 and 16-18, respectively.
Conclusion: Iranian tea brands had significant difference with international tea brands in physicochemical properties and organoleptic attributes except in total ash and microbial quality, which were not different significantly.

Background: Rice bran is a rich source of proteins, dietary fiber and bioactive compounds. In the past, it was thrown as a waste or used as animal feed. Keeping in mind, the nutritional and health benefits of rice bran, an attempt is made to produce ready-to-eat snack product using twin screw extruder.
Methods: In the present study, rice flour, corn flour and deoiled rice bran mixtures were used for the production of twin screw extruded products with good nutritional value. The experiments were conducted by varying the proportions of Rice Flour (RF), Deoiled Rice Bran (DRB), moisture content of raw flours (13-17%), screw speed (275-375 rpm) and die temperature (100-140 A°C) using central composite rotatable design. The composition of Corn Flour (CF) was kept fixed at 10% in all the experimental runs. Second order quadratic regression model fitted adequately in the variation. The significances of all terms in the polynomial were judged statistically by computing the F-value at probability (p) of 0.01 or 0.05.
Results: The physical properties like Lateral Expansion (LE) and Bulk Density (BD) were significantly affected by different process and machine parameters. Increasing feed moisture content results in a higher density and lower expansion while increasing barrel temperature and screw speed reduced density but increased expansion of extrudates. The optimum conditions obtained for the different variables were 17.73(%) deoiled rice bran, 13.94 (%) feed moisture content, 294.68 (rpm) screw speed and 123.83 A°C barrel temperature to produce acceptable extrudates

Antioxidant Properties and Glucose Uptake Effect of Ethanol Extracts from Different Sweet Potato Leaves Prepared by Lyophilization and Oven- Drying at 40 °C by Kuan-Hung Lin, Penk-Yeir Low, Pi-Yu Chao, Ming-Chih Shih, Ming-Chang Chiang, Yung-Chang Lai, Swi-Bea Wu (227-236).
Background: This study evaluated the antioxidant activities and alleviation of insulin resistance of three Sweet Potato Leaf Extracts (SPLE) with 70% ethanol prepared by lyophilization and oven-drying 40 A°C.
Methods: Content of total phenols, flavonoids, total anthocyanins, and anthocyanidin composition was analyzed. Moreover, DPPH radicals, Trolox equivalent antioxidant capacity, and ferrous ironchelating activity were determined. Cell culture and viability test and effect of plant extracts on glucose uptake were also studied.
Results: For total phenol, flavonoid, and anthocyanin contents, both CYY98 and TN64 showed better antioxidant contents than did CN1927. Anthocyanidin compositions of cyanidin and malvidin were both rich in lyophilized CYY98. The 40 A°C-dried CN1927 had significantly lower DPPH radical-scavenging activity than the other tested samples. Red leaves showed a higher ABTS-scavenging efficacy than CN1927 and CYY98 for each processing method. The 40 A°C dried CYY98 had the highest iron-chelating capacity. EC50 values of the iron-chelating activity of all lyophilized leaves of each variety were higher than those 40 A°C dried leaves. The highest improvement in insulin-resistant FL83B cells was achieved by 40 A°C drying of TN64. Relative expression levels of the insulin receptor and IR substrate-1 in hepatocyte cells significantly increased by lyophilization of CN1927, 40 A°C drying of TN64, and lyophilization of CYY98. All SPLEs treatments significantly increased expressions of glucose transporter-2 relative to that of a tumor necrosis factor-α -treated group.
Conclusion: The lyophilized CN1927 and CYY98 SPLEs, and 40 A°C-dried TN64 can improve TNF-α -induced insulin resistance by activating insulin signaling, thus resulting in increased glucose uptake.