Polyphenolic composition and antioxidant activity of the under-utilised Prunus mahaleb L. fruit.

BACKGROUND: The identification of novel plant-based functional foods or nutraceutical ingredients that possess bioactive properties with antioxidant function has recently become important to the food, nutraceutical and cosmetic industries. This study evaluates the polyphenolic composition, identifies bioactive compounds and assays the total antioxidant capacity of Prunus mahaleb L. fruits collected from different populations and sampling years in the countryside around Bari (Apulia Region, Italy). RESULTS: We identified nine polyphenolic compounds including major anthocyanins, coumaric acid derivatives and flavonols from P. mahaleb fruits. The anthocyanin content (in some populations > 5 g kg(-1) fresh weight; FW) in the fruit was comparable to that reported for so-called superfruits such as bilberries, chokeberries and blackcurrants. Coumaric acid derivatives comprised a large portion of the total polyphenolic content in the P. mahaleb fruits. Antioxidant activities, assessed using ORAC and TEAC assays, measured up to 150 and 45 mmol Trolox equivalents kg(-1) FW, respectively. Therefore antioxidant capacity of P. mahaleb fruits is relatively high and comparable to that of superfruit varieties that are often used in commercial nutraceutical products. CONCLUSION: Our findings suggest that mahaleb fruit (currently not consumed fresh or used in other ways) could serve as a source of bioactive compounds and therefore find interest from the functional food and nutraceutical industries, as a natural food colorant and antioxidant ingredient in the formulation of functional foods. © 2015 Society of Chemical Industry.

Poor thiamin and riboflavin status is common among women of childbearing age in rural and urban Cambodia.

BACKGROUND: Thiamin deficiency in infancy is the underlying cause of beriberi, which can be fatal without rapid treatment. Reports of thiamin deficiency are common in Cambodia; however, population representative data are unavailable. Because B-complex vitamin deficiencies commonly occur in combination, riboflavin was also investigated. OBJECTIVE: We determined the biomarker status of thiamin and riboflavin in women of childbearing age in rural and urban Cambodia. METHODS: We measured thiamin (erythrocyte thiamin diphosphate; TDP) and riboflavin (erythrocyte glutathione reductase activity coefficient; EGRac) status in a representative sample of Cambodian women (aged 20-45 y) in urban Phnom Penh (n = 146) and rural Prey Veng (n = 156), Cambodia, and, for comparison purposes, in a convenience sample of women in urban Vancouver, British Columbia, Canada (n = 49). RESULTS: Thiamin insufficiency (TDP ≤ 90 nmol/L) was common among both urban (39%) and rural (59%) Cambodian women (P < 0.001), whereas <20% of Vancouver women were thiamin insufficient (P < 0.001). The prevalence of suboptimal and deficient riboflavin status (EGRac ≥ 1.3) was 89%, 92%, and 70% among women in Phnom Penh, Prey Veng, and Vancouver, respectively (P < 0.001). CONCLUSIONS: Suboptimal status of both thiamin and riboflavin were common in Cambodian women, with substantially higher rates among women living in rural Prey Veng than in urban Phnom Penh. Strategies may be needed to improve the thiamin and riboflavin status of women in Cambodia. The unexpected finding of high riboflavin inadequacy status in Vancouver women warrants further investigation.

Wheat rolls fortified with microencapsulated L-5-methyltetrahydrofolic acid or equimolar folic acid increase blood folate concentrations to a similar extent in healthy men and women.

Mandatory folic acid fortification of grains such as wheat flour has been introduced in several countries to reduce the incidence of neural tube defects. There are concerns, however, that folic acid could mask the hematologic signs of vitamin B-12 deficiency and lead to other adverse health outcomes in the population. Calcium L-5-methyltetrahydrofolic acid (L-5-MTHF), a synthetic form of reduced folate, should not mask vitamin B-12 deficiency and may be safer than folic acid. Unfortunately, L-5-MTHF is not stable in most food matrices such as bread. Microencapsulation of L-5-MTHF with sodium ascorbate and a modified starch is effective at preventing loss of the vitamin during baking and storage. Our aim was to assess the efficacy of wheat rolls fortified with microencapsulated L-5-MTHF or equimolar folic acid compared with wheat rolls containing no added folate (placebo) at increasing blood folate concentrations during 16 wk. Healthy men and women aged 18-45 y (n = 45) were randomly assigned to consume wheat rolls that contained L-5-MTHF (452 µg/d), the molar equivalent of folic acid (400 µg/d), or placebo. At 16 wk, the mean (95% CI) erythrocyte folate was 0.48 (0.27, 0.71) and 0.37 (0.17, 0.57) µmol/L higher in the L-5-MTHF (P < 0.001) and folic acid wheat roll (P = 0.001) groups, respectively, than in the placebo group. Likewise, the mean plasma folate was 23 (12, 34) and 23 (12, 34) nmol/L higher in the L-5-MTHF (P < 0.001) and folic acid wheat roll (P < 0.001) groups, respectively, than in the placebo group. There were no significant differences in blood folate concentrations between the L-5-MTHF and folic acid wheat roll groups. Both microencapsulated L-5-MTHF and folic acid-fortified wheat rolls increased blood folate concentrations compared with placebo.

Neuron-Derived Exosomes Promote the Recovery of Spinal Cord Injury by Modulating Nerve Cells in the Cellular Microenvironment of the Lesion Area.

During spinal cord injury (SCI), the homeostasis of the cellular microenvironment in the injured area is seriously disrupted, which makes it extremely difficult for injured neurons with regenerative ability to repair, emphasizing the importance of restoring the cellular microenvironment at the injury site. Neurons interact closely with other nerve cells in the central nervous system (CNS) and regulate these cells. However, the specific mechanisms by which neurons modulate the cellular microenvironment remain unclear. Exosomes were isolated from the primary neurons, and their effects on astrocytes, microglia, oligodendrocyte progenitor cells (OPCs), neurons, and neural stem cells were investigated by quantifying the expression of related proteins and mRNA. A mouse SCI model was established, and neuron-derived exosomes were injected into the mice by the caudal vein to observe the recovery of motor function in mice and the changes in the nerve cells in the lesion area. Neuron-derived exosomes could reverse the activation of microglia and astrocytes and promote the maturation of OPCs in vivo and in vitro. In addition, neuron-derived exosomes promoted neurite outgrowth of neurons and the differentiation of neural stem cells into neurons. Moreover, our experiments showed that neuron-derived exosomes enhanced motor function recovery and nerve regeneration in mice with SCI. Our findings highlight that neuron-derived exosomes could promote the repair of the injured spinal cord by regulating the cellular microenvironment of neurons and could be a promising treatment for spinal cord injury.

Optimization of Heat Treatment for 38Si7 Spring Steel with Excellent Mechanical Properties and Controlled Decarburization.

Optimizing the heat treatment procedure with 13 mm diameter 38Si7 spring steel is critical for developing high-performance, low-cost, large spring steel for railway clips. The effects of quenching temperature, holding time, tempering temperature, and tempering time on the microstructure and mechanical properties were investigated using an orthogonal experiment, designed with four factors and three levels. The best heat treatment settings were explored, as well as the variation laws of mechanical properties, decarburization behavior, and fracture morphology. The results demonstrated that quenching temperature and tempering temperature had the most impact on plasticity and tempering temperature, while time had the most effect on strength. The optimized heat treatment schemes made the elongation increase by up to 106% and the reduction in area increase by up to 67%, compared with the standard BS EN 10089-2002, and there were mixed fractures caused by ductility and brittleness. The fracture tests showed a good performance of 20.2 GPa·%, and the heat treatment processes' minimum decarburization depth of 93.4 µm was determined. The optimized process would obtain stronger plastic deposition and better decarburization performance. The microstructure was simply lightly tempered martensite, and the matrix still retained the acicular martensite. The optimal heat treatment process is quenching at 900 °C for 30 min (water cooling), followed by tempering at 430 °C for 60 min (air cooling). The research led to a solution for increasing the overall mechanical characteristics and decreasing the surface decarburization of 38Si7 spring steel with a diameter of 13 mm, and it set the foundation for increasing the mass production of railway clips of this size.

Overexpression of transcription factor ZmPTF1 improves low phosphate tolerance of maize by regulating carbon metabolism and root growth.

A bHLH (basic helix-loop-helix domain) transcription factor involved in tolerance to Pi starvation was cloned from Zea mays with an RT-PCR coupled RACE approach and named ZmPTF1. ZmPTF1 encoded a putative protein of 481 amino acids that had identity with OsPTF1 in basic region. Real-time RT-PCR revealed that ZmPTF1 was quickly and significantly up-regulated in the root under phosphate starvation conditions. Overexpression of ZmPTF1 in maize improved root development, enhanced biomass both in hydroponic cultures and sand pots, and the plants developed more tassel branches and larger kernels when they were grown in low phosphate soil. Compared with wild type, overexpressing ZmPTF1 altered the concentrations of soluble sugars in transgenic plants, in which soluble sugars levels were lower in the leaves and higher in the roots. Overexpression of ZmPTF1 enhanced the expression of fructose-1,6-bisphosphatase and sucrose phosphate synthase1 participated in sucrose synthesis in the leaves but decreased them in the root, and reduced the expression of genes involved in sucrose catabolism in the roots. The modifications on the physiology and root morphology of the plants enhanced low phosphate tolerance and increased the yield under low phosphate conditions. This research provides a useful gene for transgenic breeding of maize that is tolerant to phosphate deficiency and is helpful for exploring the relationship between sugar signaling and phosphate concentrations in cells.

Enhancing the natural folate level in wine using bioengineering and stabilization strategies.

Folate deficiency is linked to many diseases, some of which may have higher probability in individuals with alcohol-induced alterations in one-carbon metabolism. Our study shows that folate content in commercial wine is not related to white or red varieties, but associated with the yeast that is used to produce the wine. The stability of folate in these wines, once opened for consumption, did not correlate with total phenolic or sulfite content. In addition, we employed yeast bioengineering to fortify wine with folate. We confirmed by overexpression that FOL2 was the key gene encoding the rate-limiting step of folate biosynthesis in wine yeast. In this study, we also show that overexpression of other folate biosynthesis genes, including ABZ1, ABZ2, DFR1, FOL1 and FOL3, had no effect on folate levels in wine. Ensuring stability of the increased natural folate in all wines was achieved by the addition of ascorbate.

Folic acid fortified milk increases blood folate to concentrations associated with a very low risk of neural tube defects in Singaporean women of childbearing age.

BACKGROUND AND OBJECTIVES: Folic acid (400 µg/d) taken during the periconceptional period reduces neural tube defect (NTD) risk by >75%. Achieving red cell folate (RCF) or plasma folate (PF) >905 nmol/L and >35 nmol/L, respectively, has been associated with a low risk of NTDs. We determined whether daily consumption of folic acid fortified milk increases blood folate concentrations to levels associated with a low risk of NTDs in Singaporean women of childbearing age. METHODS AND STUDY DESIGN: In this double-blind placebo-controlled trial, 70 non-pregnant women (21-35 y) were randomly assigned to receive fortified milk (FM) powder providing 400 µg folic acid per day or unfortified placebo milk (PM) powder for 12 weeks. Blood samples were collected at baseline and at 6 and 12 weeks. RESULTS: At 12 weeks, mean (95% CI) RCF and PF concentrations were 376 (240, 512) and 39 (26, 51) nmol/L higher in the FM group compared with the PM group (p<0.001). Of the women receiving FM, 71% (n=25) and 86% (n=30) achieved a RCF and PF associated with a very low risk of NTDs, respectively. CONCLUSION: Folic acid fortified milk increased blood folate concentrations in women of childbearing age to levels associated with a reduced risk of an NTD-affected pregnancy.

Stability of microencapsulated L-5-methyltetrahydrofolate in fortified noodles.

Here we report on the comparative stability of free and microencapsulated L-5-methyltetrahydrofolate (L-5-MTHF) with free folic acid (FA) when exposed to thermal cooking conditions that are common to noodle making. Fortifying noodle flour with free L-5-MTHF produced the greatest loss of the vitamin when noodles were cooked. In contrast, the percentage recovery of microencapsulated L-5-MTHF in both fresh and cooked noodles was not significantly different to noodles that were similarly processed with fortified FA. The addition of sodium ascorbate along with L-5-MTHF enabled a sustained stability of the folate after boiling, and also after frying. The dispersal of microencapsulated folate in flour showed better homogeneity compared to similar practices used with free form L-5-MTHF and FA, respectively. We conclude that microencapsulating L-5-MTHF along with sodium ascorbate is effective to produce a stable folate in fortified noodles, a staple food for Asian populations that may require improved dietary folate intake.

Microencapsulation of L-5-methyltetrahydrofolic acid with ascorbate improves stability in baked bread products.

Fortification of foods with L-5-methyltetrahydrofolic acid (L-5-MTHF) is challenging due to low stability to environmental conditions that include exposure to pH, moisture, and temperature. The objective of the present study was to stabilize L-5-MTHF using microencapsulation technology. L-5-MTHF microcapsules constructed with different core-to-wall ratios of L-5-MTHF, both alone or in combination with sodium ascorbate, yielded high (>89%) recovery of L-5-MTHF. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) analysis confirmed successful encapsulation of L-5-MTHF with high core-to-wall ratios. Microencapsulation of L-5-MTHF alone with a high core-to-wall ratio significantly (p < 0.05) improved the stability of L-5-MTHF over the course of bread baking, performed both in pilot plant and in commercial baking conditions. Breads made with fortified flour containing sodium ascorbate coencapsulated with L-5-MTHF had recoveries of L-5-MTHF that were 97% and 77%, respectively, for pilot plant and bakery breads. Co-encapsulating L-5-MTHF with ascorbate also significantly (p < 0.05) improved stability during storage, as compared to breads that contained free L-5-MTHF.

The use of cyclic voltammetry to study the oxidation of l-5-methyltetrahydrofolate and its preservation by ascorbic acid.

A cyclic voltammetry study of 1mM l-5-methyltetrahydrofolate (l-5-MTHF) was performed in pH 5.5 Britton-Robinson buffer at room temperature to study the stability of l-5-MTHF alone and in combination with ascorbic acid (AA). The degradation of l-5-MTHF and AA over a period of 12h both followed first order reaction kinetics. Using this technique, oxidation peaks of l-5-MTHF were identified at +0.17 and +1.18V, and another oxidation peak appeared after 4h under air at +0.89V. Cyclic voltammetry and HPLC quantification enable us to confirm that l-5-MTHF can be highly preserved by the addition of an equimolar concentration of AA. This treatment was equivalent to a purge of nitrogen used to remove oxygen and thus minimise oxidation of l-5-MTHF when present in aqueous solutions. HPLC confirmed the fact that a full regeneration of oxidised l-5-MTHF occurred with the addition of sodium ascorbate, thus denoting that the redox character of l-5-MTHF can be controlled by the presence of reducing agents. Cyclic voltammetry proved to be a sensitive and accurate method for characterising l-5-MTHF oxidation and potential preservation with ascorbic acid. To our knowledge, this is the first study that has demonstrated the number of oxidation sites on l-5-MTHF.

Studies on the retention of microencapsulated l-5-methyltetrahydrofolic acid in baked bread using skim milk powder.

Our aim was to protect l-5-methyltetrahydrofolic acid (L-5-MTHF) from degradation throughout the baking and storage of a fortified white bread using microencapsulation. L-5-MTHF, with or without sodium ascorbate (ASC), was microencapsulated using skim milk powder (SMP) as the coating agent. Recoveries of L-5-MTHF in spray-dried materials were greater than 95 ± 5%. Microencapsulated L-5-MTHF was completely released from the skim milk coating material in simulated gastric fluid within the first 10 min at 37°C. Incorporation of SMP-L-5-MTHF or SMP-L-5-MTHF+ASC into bread gave recoveries of 81.3 ± 1.3% and 87.1 ± 1.2% (n=3), respectively, for L-5-MTHF immediately after bread baking. These treatments also showed significantly (p<0.05) greater L-5-MTHF stability during room temperature storage, compared to the free L-5-MTHF. This study has shown that SMP is an effective microencapsulating agent and in the presence of ASC will produce excellent conditions for stabilising L-5-MTHF in baked bread.

Thermal oxidation studies on reduced folate, L-5-methyltetrahydrofolic acid (L-5-MTHF) and strategies for stabilization using food matrices.

The thermal stability of L-5-methyltetrafolic acid (L-5-MTHF) was investigated in model/buffer systems and food systems. L-5-MTHF degradation followed first-order reaction kinetics with relatively greater (P < 0.01) stability at pH 4 compared to pH 6.8 in the buffer systems. This was confirmed using cyclic voltammetry. The stability (for example, k-values) of L-5-MTHF in an oxygen controlled environment improved (P < 0.001) proportionally when in the presence of increasing molar ratios of sodium ascorbate (NaAsc). The addition of NaAsc to L-5-MTHF after heat treatment was also effective at returning thermally oxidized L-5-MTHF back to its original form. A scheme was developed to explain the degradation and regeneration of L-5-MTHF. The importance of antioxidant protection of L-5-MTHF from thermal oxidation was extended using 2 distinct food systems; namely skim milk and soy milk, both with known antioxidant capacities. We conclude that the antioxidant activity of food components can enhance the stability of L-5-MTHF.