Antioxidant Stability in Vegetable Oils Monitored by the ASTM D7545 Method

The PetroOXY method was used to evaluate the kinetics of oxidation of two edible vegetable oils, extracted from moringa and passion fruit. This method, which uses pure oxygen at 700 kPa is effective and fast and our experiments were carried out at temperatures 110–140 °C with BHA antioxidant additive concentration ranging from 0 to 500 ppm. Moringa and passion fruit oils followed first-order kinetics although, in the case of passion fruit oil, mathematical approximations in the first-order kinetic expression resulted in a final equation that could also be interpreted as deriving from zero-order kinetics. The higher stability of moringa oil was characterized by an activation enthalpy ca. 50 % higher than the one related to passion fruit oil.     

Fast headspace-enantioselective GC-mass spectrometric-multivariate statistical method for routine authentication of flavoured fruit foods

This study describes a rapid total analysis system (TAS) to detect the authenticity of fruit-flavoured foods and beverages by on-line combining headspace solid phase microextraction (HS-SPME) with enantioselective GC-MS (Es-GC-MS) and statistical multivariate methods (PCA, HCA). Peach, coconut, apricot, raspberry, as fruits mainly characterised by γ- and δ-lactones as chiral markers, strawberry (α-ionone, linalool, nerolidol, ethyl 2-methylbutyrate, 2-methylbutyric acid and γ-lactones) and melon (ethyl 2-methylbutyrate and 2-methylbutanol) were investigated. The system was developed by (a) optimising non-equilibrium HS-SPME sample preparation, (b) speeding-up ES-GC using cyclodextrin derivatives as chiral selectors with conventional and narrow-bore columns and (c) elaborating data by multivariate methods. The resulting TAS affords a reduction of the time needed for the whole analytical process from about 150 min to 20-50 min (67-87% of the current routine method) depending on matrix, sampling and analysis conditions and Es-GC columns.     

Essential oil nanoemulsions: antibacterial activity in contaminated fruit juices

Many human acid tolerant bacterial and fungal pathogens can be transmitted through the consumption of the contaminated fruit juices. We aim to formulate essential oil nanoemulsions (basil, black seed, turmeric, clove & cinnamon), determine their ability to clear contamination by food borne bacterial pathogens from fruit juices. The antibacterial activity of the optimised formulations was tested in the fruit juices against bacterial pathogens causing gastrointestinal tract infections. The minimum bactericidal concentration (MBC) of clove emulsions ranged from 15.6 to 25 μL mL⁻¹. Cinnamon oil emulsion had an MBC ranging between 15 and 31 μL mL⁻¹. At MBC, cinnamon oil emulsions caused a 6log₁₀ decrease in viable counts by 8 h and maintained the sterility of fruit juices for 7 days at ambient temperature. Thus, clove and cinnamon microemulsions can be used as juice additives to control food borne bacterial pathogens and maintain the bacterial sterility of fruit juices.     

A comprehensive meta-analysis on evidence of Mediterranean diet and cardiovascular disease: Are individual components equal?

Many studies have reported that higher adherence to Mediterranean diet may decrease cardiovascular disease (CVD) incidence and mortality. We performed a meta-analysis to explore the association in prospective studies and randomized control trials (RCTs) between Mediterranean diet adherence and CVD incidence and mortality. The PubMed database was searched up to June 2014. A total of 17 studies were extracted and 11 qualified for the quantitative analysis. Individuals in the highest quantile of adherence to the diet had lower incidence [relative risk (RR): 0.76, 95% confidence intervals (CI): 0.68, 0.83] and mortality (RR: 0.76, 95% CI: 0.68, 0.83) from CVD compared to those least adherent. A significant reduction of risk was found also for coronary heart disease (CHD) (RR: 0.72, 95% CI: 0.60, 0.86), myocardial infarction (MI) (RR: 0.67; 95% CI: 0.54, 0.83), and stroke (RR: 0.76; 95% CI: 0.60, 0.96) incidence. Pooled analyses of individual components of the diet revealed that the protective effects of the diet appear to be most attributable to olive oil, fruits, vegetables, and legumes. An average reduced risk of 40% for the aforementioned outcomes has been retrieved when pooling results of RCTs. A Mediterranean dietary pattern is associated with lower risks of CVD incidence and mortality, including CHD and MI. The relative effects of specific food groups should be further investigated.     

Betacyanins in dragon fruit peels: the kinetic models of their degradation under different treatment conditions

In this study, after purification, the content of betacyanins in dragon fruit peels was 9.22 mg g⁻¹ dry sample. The stability of betacyanins under the effect of different concentration of metal cation (K⁺, Na⁺, Cu²⁺, Fe²⁺, Fe³⁺, Mg²⁺, Al³⁺) solutions and sugars (glucose, sucrose, fructose, maltose and lactose) solutions was observed. The results showed that 10% lactose and 0.08 mol L⁻¹ potassium chloride solution increased the stability of betacyanins and could be used as stabiliser agents. The degradation reaction under different temperatures (20, 30, 40, 50, 60, 70, 80 °C), pH (2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0) and light conditions (light and dark) of mixed solution (betacyanins and stabiliser), including aqueous pigments solution (APS), lactose pigments solution (LPS) and potassium chloride pigments solution (PCPS), accorded with the first-order reaction kinetics. The t_1/2 values (the hours needed for 50.0% degradation of betacyanins) of LPS even up to 330.0 h at 20 °C and dark condition.     

采后果实链格孢属真菌病害防治方法研究进展

链格孢属真菌(Alternaria spp.)可引起多种果实采后发生病害,每年造成的损失异常严重,因此防治由链格孢属真菌引起的采后果实病害显得尤为迫切。文章将着重介绍国内外研究中采后果实链格孢属真菌病害的防治方法,包括采前防治,采后物理、化学和生物方法及联合防治等,并提出在未来的发展中应该使用新的、有效的组合方式来提高防治效果,增强果实抵抗链格孢属真菌的能力,延长果实采后贮藏期,提升其商品价值。     

Effects of hydrogen sulphide on quality and antioxidant capacity of mulberry fruit

Here we investigated the effect of hydrogen sulphide (H₂S) on postharvest quality of mulberry fruit and possible underlying mechanisms. Endogenous H₂S content first increased after harvest and then decreased sharply with the process of ripening and senescence. A fumigation with H₂S released from 0.8 mm NaHS solution could significantly enhance the endogenous H₂S content by increasing the activities of D‐cysteine desulfhydrase and L‐cysteine desulfhydrase. NaHS could significantly slow down the ripening rate of mulberry fruit and reduce the respiratory intensity and anthocyanin content. Moreover, H₂S fumigation was able to obviously delay or slow down the decreases in soluble protein, titratable acidity and ascorbate contents. Further results showed that activities of representative antioxidant enzymes in H₂S‐treated sample were higher than those of control samples during storage, resulting in a decrease in superoxide anion production. Together, these results clearly indicate that H₂S fumigation has a potential role in the preservation of mulberries.     

Improving supercritical water gasification of sludge by oil palm empty fruit bunch addition: Promotion of syngas production and heavy metal stabilization

The co-gasification of sewage sludge and palm oil empty fruit bunch (EFB) in supercritical water (SCW) was conducted at 400℃ with a pressure of over 25 MPa. This study aimed to investigate the influence of EFB addition on the syngas production and its composition. The heavy metal distribution and the leaching potential of the solid residue were also assessed. The results showed that syngas yield significantly increased with the addition of EFB into the feedstock. The cold gas efficiency (CGE) and carbon efficiency (CE) of co-gasification were higher than those of individual gasification. The actual syngas production from co-gasification of sludge and EFB was 45% higher than the theoretical total volume. The results indicated that the addition of EFB to sludge had the synergetic promotion effect on syngas production from sludge and EFB in supercritical water. This enhancement might be due to the dissolution of alkali metals from EFB and the adjustment of organic ratio. In addition, higher percentage of heavy metals were deposited and stabilized in the solid residue after SCWG. The leaching concentration of heavy metals from the solid residues was decreased to a level below the standard limit which enables it to be safely disposed of in landfill. In conclusion, the EFB addition has been proved to promote syngas production, as well as, stabilize the heavy metal in solid residues during co-SCWG.     

果品分级检测技术的研究现状及发展

我国是水果生产第一大国,水果采收后处理分级有利于销售按级定价,方便贮运;通过检测剔除虫害果和机械损伤果,减轻了病虫害的传播和降低残次品处理成本;对于提高我国果品品质,增强国际市场竞争力有着重要的意义。通过对国内分级检测的技术方法的介绍,分析了目前分级检测技术的不足,提出了相关的发展建议。     

Influence of drying conditions on colour,betacyanin content and antioxidant capacities in dried red-fleshed dragon fruit (Hylocereus polyrhizus)

In this study, drying of red-fleshed dragon fruit at different temperatures (40, 50, 60, 70 and 80 °C) and air velocities (1.0 and 1.5 m s⁻¹) was conducted under the specific humidity of 25 g H₂O kg⁻¹ dry air. The results showed that drying at higher temperatures resulted in shorter drying times. However, temperature and air velocity did not significantly affect the total betacyanin contents and antioxidant capacities in dried products. Seven betacyanins identified by LC-MS were betanin, isobetanin, phyllocactin, isophyllocactin, betanidin 5 –O-(6′O-3-hydroxybutyryl)-β-glucoside, isobetanidin 5 –O-(6′O-3-hydroxybutyryl)-β-glucoside and decarboxylated phyllocactin. In addition, the temperature increased the isomerisation of betacyanins. The most preferable condition for preserving the colour and betacyanin contents of red-fleshed dragon fruit was the drying at a temperature of 80 °C and air velocity of 1.5 m s⁻¹ since it could shorten the drying time and give a bright red colour to the dried product as well as it had no significant impact on the betacyanins.