Production and characterization of α-linolenic acid enriched structured lipids from lipase-catalyzed interesterification

The purpose of this study was to enrich α-linolenic acid (ALA) on the triacylglycerol (TAG) molecules of the selected vegetable oils (soybean and corn oil) in order to synthesized structural lipid (SL) with low ω6 to ω3 ratio. SLs were synthesized by lipase-catalyzed interesterification of soybean (SO) and corn oil (CO) with perilla oil (PO). Lipozyme RM IM from Rhizomucor miehei (5% by weight of total substrate) was used for the reaction. The reaction was performed during 24 hr at 55°C in the stirred-batch type reactor with solvent free system. After 24 hr reaction the ratio of ω6 to ω3 in SL products dramatically decreased comparing to that of substrates (SO and CO) before the reaction. At sn-2 position, the contents of ALA were 25.99% in soybean-SL and 23.25% in corn-SL, respectively. According to the equivalent carbon number (ECN) of TAG profile, newly produced SLs were separated by reverse-phase high performance liquid chromatography (HPLC). These results indicated that lipase-catalyzed interesterification is effective to produce SL with low ω6 to ω3 ratio which might be used as health beneficial oil.     

Trans fatty acids content and fatty acid profiles in the selected food products from Korea between 2005 and 2008

Since a high intake of trans fatty acids (TFA) has been associated with the increased risk of developing cardiovascular disease, food regulation worldwide has been amended with respect to nutrition labeling and health claims on TFA. In the present study, the TFA levels of Korean food products were investigated to assess the regulation effect of TFA labeling. Same Korean food products within 7 different categories were purchased in years 2005 and 2008, and the contents of TFA and lipid and fatty acid composition were investigated. Lipid and TFA contents decreased in all food products manufactured in 2008. TFA levels were 0.01 to 6.88 g/100 g food in 2005, but the levels remarkably decreased to nondetectable level or up to 0.5 g TFA/100 g food in 2008. The foods from 2005 contained a various level of TFA ranging 0.6% to 44.6% of total fatty acids; however, the TFA level significantly decreased in most foods up to 3.8% from year 2008. For TFAs, trans C18:1 levels were greater than trans isomers of C18:2, and the levels in 2005 were significantly reduced in 2008 (P < 0.05). TFA levels at the sn-2 position were up to 48.3% of total fatty acids in 2005, but the level considerably decreased up to 5.4% in 2008. The considerably decreased content of TFA in 2008 suggested that food manufacturers recognized the adverse effect of TFA on human health and followed the compulsory trans fat labeling rule by Korean Food and Drug Administration (KFDA), which started December 2007.     

Studies of reaction variables for lipase-catalyzed production of alpha-linolenic acid enriched structured lipid and oxidative stability with antioxidants

Alpha-linolenic acid (ALA) enriched structured lipid (SL) was produced by lipase-catalyzed interesterification from perilla oil (PO) and corn oil (CO). The effects of different reaction conditions (substrate molar ratio [PO/CO 1:1 to 1:3], reaction time [0 to 24 h], and reaction temperature [55 to 65 °C]) were studied. Lipozyme RM IM from Rhizomucor miehei was used as biocatalyst. We obtained 32.39% of ALA in SL obtained under the optimized conditions (molar ratio-1:1 [PO:CO], temperature-60 °C, reaction time-15 h). In SL, the major triacylglycerol (TAG) species (linolenoyl-linolenoyl-linolenoyl glycerol [LnLnLn], linolenoyl-linolenoyl-linoleoyl glycerol [LnLnL]) mainly from PO and linoleoyl-linoleoyl-oleoyl glycerol (LLO), linoleoyl-oleoyl-oleoyl glycerol (LOO), palmitoyl-linoleoyl-oleoyl glycerol (PLO) from CO decreased while linolenoyl-linolenoyl-oleoyl glycerol (LnLnO) (18.41%), trilinolein (LLL) (9.06%), LLO (16.66%), palmitoyl-linoleoyl-linoleoyl glycerol (PLL) (9.69%) were increased compared to that of physical blend. Total tocopherol content (28.01 mg/100 g), saponification value (SV) (192.2), and iodine value (IV) (161.9) were obtained. Furthermore, oxidative stability of the SL was also investigated by addition of 3 different antioxidants (each 200 ppm of rosemary extract [SL-ROS], BHT [SL-BHT], catechin [SL-CAT]) was added into SL and stored in 60 °C oven for 30 d. 2-Thiobabituric acid-reactive substances (TBARS) value was 0.16 mg/kg in SL-CAT and 0.18 mg/kg in SL-ROS as compared with 0.22 mg/kg in control (SL) after oxidation. The lowest peroxide value (POV, 200.9 meq/kg) and longest induction time (29.88 h) was also observed in SL-CAT.     

Antioxidative activities of mao feng tea (Camellia spp.) and kamtae (Ecklonia cava) extracts and their effects on structured lipid from corn and perilla oil

In the study, solvent extracts of kamtae (Ecklonia cava) and mao feng tea (Camillia sinensis) were used for obtaining different fractions of organic solvents (diethyl ether, butanol, and ethyl acetate) and the extracted fractions were studied for their antioxidative activities. The total phenolic contents of the mao feng tea ranged from 1.44 to 5.97 mM GAE/g while kamtae ranged from 1.13 to 4.41 mM GAE/g, respectively. Among them, ethyl acetate fraction showed the highest content of phenolic compounds, resulting in Trolox equivalent antioxidant capacity (TEAC) values as 1,554.54 (from mao feng tea) and 1,097.63 mM Trolox E/g (from kamtae). Also, ethyl acetate fractions from mao feng tea showed the highest DPPH (89.27 RSC%), superoxide anion scavenging activity (46.58%), and ferric reducing antioxidant power (FRAP) (242.2 mg GAE/g) while ethyl acetate fractions from kamtae (K-EA) showed the highest DPPH (82.23 RSC%), superoxide anion scavenging activity (28.82%), and FRAP (162.43 mg GAE/g) among the obtained fractions.     

Nuclear and isotopic techniques application used in supporting nutritional studies in Latin America countries

The global nutrition community recognizes the usefulness of nuclear and isotopic techniques and especially stable isotopes for accurate measurements in key areas of human nutrition and health. Although progress has been made in many Latin America countries in reducing the absolute number of undernourished people, food policy and public health communities have to face the double burden on health. On one side they have to address the prevention of obesity and on the other side they are trying to reduce undernutrition. However, to be successful in development of sustainable nutrition programs, a combination of relevant scientific knowledge and approaches that are practical is required to assure even a reasonable level of success. The objectives of this review are to highlight the role of isotopic techniques in nutritional studies and to review the role of the International Atomic Energy Agency in supporting nutrition interventions in Latin America countries.