The L513S polymorphism in medium-chain acyl-CoA synthetase 2 (MACS2) is associated with risk factors of the metabolic syndrome in a Caucasian study population

Enzymes of the medium-chain acyl-CoA synthetase (MACS) family catalyze the ligation of medium chain fatty acids with CoA to produce medium-chain-acyl-CoA. At least four members of the MACS gene family are clustered on human chromosome 16p12. Association studies in the Japanese Suita cohort of MACS polymorphisms and various phenotypes revealed the contribution of the Leu513Ser polymorphism in MACS2 to multiple risk factors of the metabolic syndrome. Here, we investigated the association between this polymorphism and different risk factors in the Caucasian Metabolic Intervention Cohort Kiel. Seven hundred and sixteen male subjects aged 45-65 years were recruited for a standard oral glucose tolerance test and the postprandial assessment of metabolic parameters after an oral metabolic tolerance test (oMTT; 1017 kcal, 51.6% fat, 29.6% carbohydrates, 11.9% protein). The MACS2 Leu513Ser polymorphism was determined by TaqMan-Assay in 705 subjects. Postprandial triglyceride levels following oMTT [area under the curve (AUC)] were significantly higher in subjects carrying the Ser allele compared to subjects homozygous for the Leu allele (1690 +/- 100 mg x h/dL versus 1514 +/- 39 mg x h/dL, p = 0.04). Significant differences between genotype groups were also found for fasting (108 +/- 1.9 mg/dL versus 104 +/- 0.66 mg/dL, p = 0.04) and postprandial (AUC 535 +/- 11 versus 512 +/- 4.0, p = 0.02) glucose levels as well as for high-density-lipoprotein, body mass index, waist circumference, systolic and diastolic blood pressure. Carriers of the Ser allele also show an increased risk of impaired glucose metabolism (OR: 1.48, 95% confidence interval: 0.98-2.27, p = 0.07), adiposity (1.8, 1.16-2.81, p = 0.01) and hypertension (1.5, 0.99-2.17, p = 0.06). In conclusion, our results suggest an involvement of the MACS2 Leu513Ser polymorphism in the development of the metabolic syndrome in Caucasian population. Additionally, the higher triglyceride and glucose levels after an oMTT support a possible functional impact of the polymorphism in vivo.     

A comprehensive review on polarity,partitioning, and interactions of phenolic antioxidants at oil–water interface of food emulsions

There has been a growing interest in developing effective strategies to inhibit lipid oxidation in emulsified food products by utilization of natural phenolic antioxidants owing to their growing popularity over the past decades. However, due to the complexity of emulsified systems, the inhibition mechanism of phenolic antioxidants against lipid oxidation is rather complicated and not yet fully understood. In order to highlight the importance of polarity of phenolic antioxidants in emulsified systems according to the polar paradox, this review covers the recent progress on chemical, enzymatic, and chemoenzymatic lipophilization techniques used to modify the polarity of antioxidants. The partitioning behavior of phenolic antioxidants at the oil–water interface, which can be influenced by the presence of synthetic surfactants and/or antioxidant emulsifiers (e.g., polysaccharides, proteins, and phospholipids), is discussed. In addition, the emerging phenolic antioxidants among phenolic acids, flavonoids, tocopherols, and stilbenes applied in food emulsions are elaborated. As well, the interactions of polar–nonpolar antioxidants are stressed as a promising strategy to induce synergistic interactions at oil–water interface for improved oxidative stability of emulsions.     

Formation of Heterocyclic Amines in Salami and Ham Pizza Toppings During Baking of Frozen Pizza

Heterocyclic amines (HAs) are formed as Maillard reaction products in the crust of meat products during heating processes. Two typical pizza toppings—salami and cooked ham—were analyzed for the presence of HAs after baking frozen pizzas at top and bottom temperatures of 250 and 230 °C, respectively. After baking pizza slices for 12 min, MeIQx (2‐amino‐3,4,8‐trimethylimidazo[4,5‐f]quinoxaline; 0.2 ng/g), 4,8‐DiMeIQx (2‐amino‐3,8‐dimethylimidazo[4,5‐f]quinoxaline; 0.5 ng/g), PhIP (2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine; 0.2 ng/g), norharman (4.5 ng/g), and harman (2.5 ng/g) were found in the ham toppings, whereas only the comutagenic norharman (107.4 ng/g) and harman (11.4 ng/g) were found in the salami toppings. The content of MeIQx and 4,8‐DiMeIQx in ham increased from 0.3 to 1.8 ng/g and 0.8 to 1.6 ng/g, respectively, when the recommended baking time was increased from 15 min (manufacturer's specification) to 18 min at 230 °C. MeIQx was formed in salami when the heating time was extended to 18 min. Moreover, higher concentrations of PhIP in salami or ham slices were found when baking temperatures were 250 °C rather than 230 °C (baking time of 12 min). However, sensory tests showed that panelists preferred longer‐baked pizzas due to an increased crispiness. Thus, results show that a substantial formation of HAs may occur in pizza toppings such as ham and salami, with ham being particularly susceptible when compared to salami. Formation of HAs increases with increasing baking time and temperature. The occurrence of the cupping of ham or salami slices during baking may also increase the formation of HAs.     

Growth inhibition of Escherichia coli O157:H7 and Listeria monocytogenes by carvacrol and eugenol encapsulated in surfactant micelles

Growth inhibition of four strains of Escherichia coli O157:H7 (H1730, F4546, 932, and E0019) and Listeria monocytogenes (Scott A, 101, 108, and 310) by essential oil components (carvacrol and eugenol) solubilized in nonionic surfactant micelles (Surfynol 465 and 485W) was investigated. Concentrations of encapsulated essential oil components ranged from 0.02 to 1.25% depending on compound, surfactant type, and surfactant concentration (0.5 to 5%). Eugenol encapsulated in Surfynol 485W micelles was most efficient in inhibiting growth of the pathogens; 1% Surfynol 485W and 0.15% eugenol was sufficient to inhibit growth of all strains of E. coli O157:H7 and three of four strains of L. monocytogenes (Scott A, 310, and 108). The fourth strain, L. monocytogenes 101, was inhibited by 2.5% Surfynol and 0.225% eugenol. One percent Surfynol 485W in combination with 0.025% carvacrol was effective in inhibiting three of four strains of E. coli O157:H7. Strain H1730 was the most resistant strain, requiring 0.3% carvacrol and 5% surfactant for complete inhibition. Growth inhibition of L. monocytogenes by combinations of carvacrol and Surfynol 465 ranged between 0.15 and 0.35% and 1 and 3.75%, respectively. Generally, the antimicrobial activity of Surfynol 465 in combination with eugenol was higher than that for the combination with carvacrol. The potent activity was attributed to increased solubility of essential oil components in the aqueous phase due to the presence of surfactants and improved interactions of antimicrobials with microorganisms.     

Developing community-based food security criteria in rural Tanzania

Food security remains a major challenge in Sub-Saharan Africa. The widely acknowledged definition of food security and its four dimensions, availability, access, utilisation and stability, are somewhat abstract in the local context of small-scale farmers. Therefore, more site-specific information on the local food situation is needed to respond to the local food security challenges. Participatory elaboration of these criteria within the rural communities is crucial. The objective of this research was to elaborate community-based criteria in four selected study villages of Tanzania. We present an adapted methodological procedure based on the so-called Framework for Participatory Impact Assessment (FoPIA). Based on a series of farmer workshops, we analysed the local understanding of food security and derived a set of food security criteria. We found that these criteria cover the three dimensions of sustainability (social, economic and environmental), while simultaneously representing the four food security dimensions, showing that rural communities think holistically and consider multiple criteria and dimensions related to food security. Our participatory methodological approach was suitable for identifying the specific development priorities that need to be addressed for improved food security in a particular locality. The locally specific food security criteria can be used for impact assessment, monitoring and evaluation and, finally, for the adaptation of development measures to local contexts.     

Influence of the suspension media on the thermal treatment of mesophilic lactococcal bacteriophages

The thermal resistances of the Lactococcus lactis phages P008 (a heat-sensitive wide-spread phage) and P680 (a heat-resistant phage) suspended in milk and in solutions supplemented with milk components were studied to elucidate the protective role of milk on phage inactivation. For both phages a decrease of inactivation was observed in casein solution. Furthermore, the inactivation kinetics of the phages in whey, in whey cream (3.5%, 20%, 30% fat) and in whey protein concentrate (0.7%, 5%, 10% protein) were tested. The inactivation experiments in whey cream and in whey protein concentrate having different concentrations of fat and protein revealed that fat had no influence on the inactivation, while, in contrast, the presence of protein had a protective effect.     

Floc volume effects in suspensions and its relevance for wastewater engineering

The aim of this paper is to better understand oxygen transfer reduction caused by floc suspensions. We demonstrate that the overall floc volume significantly influences oxygen transfer depletion. Submerged fine bubble and coarse bubble diffusers are affected in the same way by this phenomenon. The mixed liquor suspended solids concentration (MLSS concentration) is not an appropriate parameter for describing or relating phenomena that are caused by the overall floc volume in activated sludge (e.g., oxygen transfer depression and sludge sedimentation characteristics). A better correlation is achieved by using the mixed liquor volatile suspended solids concentration (MLVSS concentration). To characterize the effects of the overall floc volume in suspensions whose MLVSS concentration cannot be determined (e.g., inorganic iron hydroxide flocs), a new method-the hydrostatic floc volume (HFV)-that approximates the overall floc volume in floc suspensions is introduced. Application of this method demonstrates that oxygen transfer depression caused by iron hydroxide flocs and activated sludge flocs is similar.     

Relationship between the physical properties of chlorogenic acid esters and their ability to inhibit lipid oxidation in oil-in-water emulsions

In oil-in-water emulsions, the physical location of antioxidants has been postulated to be one of the most important factors impacting activity. The purpose of this research was to examine how the esterification of various hydrocarbon chains (C₄, C₈, or C₁₂) onto chlorogenic acid (CGA) influenced physical properties and antioxidant activity in menhaden oil-in-water emulsions. Both surface activity and partitioning of CGA and its hydrocarbon esters into the lipid phase of oil-in-water emulsions increased with increasing size of the hydrocarbon chain. When CGA and its esters were added to a menhaden oil-in-water emulsion at concentration that resulted in equal free radical scavenging activity, CGA, butyl CGA and octyl CGA had similar antioxidant activity while dodecyl CGA was ineffective. These results suggest that phenolic antioxidants conjugated with hydrocarbon chains are more highly associated with lipid emulsions droplets, but these changes in physical properties did not increase antioxidant activity.