How natural dietary antioxidants in fruits, vegetables and legumes promote vascular health

Oxidative stress disturbs the normal redox state within the human body, and thus may trigger many human chronic diseases including cardiovascular disease. Antioxidant properties of some bioactive components in plant-based foods have been proposed to be capable of controlling such disturbances. This hypothesis has initiated a great number of laboratory studies devoted to the understanding of the role of natural antioxidants in cardio-health promotion. This review summarizes these studies with an emphasis on major natural antioxidants found in three categories of plant-based foods (fruits, vegetables and legume) and mechanisms that these antioxidants may use in promoting cardio-health. Since different food categories possess different bioactive compounds with various antioxidant capacities, specific foods, when consumed together, may produce synergistic antioxidant interactions and in turn have more positive physiological effects on cardio-health than when consumed alone. This review also highlights research on antioxidant synergisms. We recommended strategically selecting foods that provide multiple levels of protection against the development of cardiovascular diseases.     

Analysis of the aroma compounds of the fruit extracts of Spondias cytherea ("ambarella") from Cameroon

 The aroma compounds of extracts of ripe and unripe fruits of Spondias cytherea Sonnerat ("ambarella" or "cajarana") were analysed by GC/FID, GC/MS and olfactometry. As main compounds, 1,8-cineole, α-pinene, β-pinene, terpinolene, limonene, α-terpineol, butyl acetate, γ-terpinene and terpinen-4-ol, among more than 50 constituents, were identified. The characteristic odour impressions of these extracts can be correlated to identified minor alcohols and esters, monoterpenes, hexane derivatives and fatty acids. Received: 6 July 1998     

臭氧在果蔬保鲜和农残降解上的应用

臭氧是一种强氧化剂，它可以杀灭果蔬上的微生物，去除果蔬释放的乙烯，抑制果蔬的呼吸作用，延长果蔬的保鲜期。臭氧还可以降解果蔬上的农药残留。尽管可能会对某些果蔬的品质造成损伤，但具有高活性、高渗透性和无毒降解产物的特点的臭氧在果蔬采后处理上有着巨大的应用潜力。     

Simultaneous Screening of 733 Pesticide Residues in Fruits and Vegetables by a GC/LC-Q-TOFMS Combination Technique

In this paper, we report the construction of two accurate mass databases and the development of a combination detection method that simultaneously screens for 733 pesticide and chemical contaminant multi-residues via high-throughput gas chromatography (GC)– and liquid chromatography (LC)–quadrupole-time-of-flight mass spectrometry (Q-TOFMS). This work demonstrates that electronic mass spectral standards may replace chemical-source standard materials as references through one sample preparation and the combination of GC/LC–Q-TOFMS screening. This cutting-edge technique has also replaced multi-residue determination using targeted detection with non-targeted screening. The pesticide residue types, sensitivity, recovery, and reproducibility of this combination technique are evaluated in eight fruit and vegetable matrices. This technique shows three advantages: ① In comparison with the discovery capability of a single technique, the combination technique shows an improvement of 51.1% (GC–Q-TOFMS) and 39.6% (LC–Q-TOFMS), respectively; ② the combination technique can satisfy a screening limit lower than 10 μg·kg⁻¹ and meet the requirements of “uniform standards,” although some of the pesticide residues could be optimized to further improve screening sensitivity; ③ over 488 pesticides with recoveries between 60% and 120% and relative standard deviation (RSD) ≤ 20% at a spiked level of 10 μg·kg⁻¹ were detected with the combination technique in eight different matrices. From 2012 to 2017, this combination technique was applied in an investigation to screen pesticide residues from 1384 sampling locations for 38 138 batched samples covering 18 categories and 134 types of fruits and vegetables obtained from across the mainland of China. After statistical analysis, 533 pesticides in 115 891 determinations were detected, and the regularity of pesticides in the fruits and vegetables sold on the Chinese market was shown.     

Carotenoid content and composition in rose hips (Rosa spp.) during ripening,determination of suitable maturity marker and implications for health promoting food products

Carotenoids are important antioxidants and valuable bioactive compounds contributing to the health benefits of different foods, and rose hips are known for high bioactive content. This study investigated the content of carotenoids and chlorophylls in hips from four rose species during the ripening period. Carotenoid content varied greatly between harvesting times, although species and year, and interactions between factors, also played an important role. Some carotenoids were identified only in hips of specific rose species. Some of the investigated compounds decreased (chlorophyll a) or increased (lycopene) consistently over the ripening period and could therefore be useful as maturity markers. An optimal content of total or specific carotenoids, e.g. for food products containing rose hips, might be obtained by proper choice of harvesting time and rose species.     

Use of sense masking to study sensory modalities singly: Interest for the understanding of apple in-mouth perception

The relative contribution of aroma, taste and texture modalities to overall perception, as well as the interactions which can occur between them, were studied during the consumption of natural foods, i.e. apples. Aroma, taste and texture perceptions were masked in that order by employing different masking agents, separately or combined, allowing one or several of these senses to be omitted during various matching tasks. By means of Common Components and Specific Weight Analysis (CCSWA), matching results were compared to those of rating tests performed by a trained panel, without masking agents. Taste was the modality which contributed most to apple discrimination, followed by texture and aroma. While taste did not seem to interact with texture, its perception may have been amplified by odorant information. A perceptual taste-taste interaction may also occur during apple consumption. The use of masking agents could thus become a useful tool to better understand the perception of several sensations of real natural foods whose formulation cannot be modulated.     

Modeling of Batch Dryers for Shrinkable Biological Materials

Design of dryers for biological materials is a complex problem, since in order to solve the model equations, foodstuff physicochemical and equilibrium properties and drying kinetics should be included as a function of water content and operating variables. Shrinkage of biological materials under dehydration must also be taken into account when the macroscopic balances in the bed of drying need to be solved. The main objective of this work was thus to develop a realistic simulation model to predict batch deep bed drying of shrinkable biological materials. Differential macroscopic balances for heat and mass transfer in the air and solid phases were expressed in moving coordinates in order to solve the problem of particle shrinkage during drying. The equation system was solved by the ‘method of lines’ using the Gear package for temporal derivatives and finite differences for spatial ones. All the parameters and physical properties required to solve the model were taken from literature or determined independently in lab-scale experiments. A pilot-scale hot air batch dryer was built in order to carry out experimental determinations during drying of slices or cylinders of potato, apple, and carrot at diverse hot air conditions. The appropriate choice of numerical method and initial conditions gave a reliable and stable solution of the equation system. The simulation results agreed closely to experimental data on deep bed batch drying of food particles under different conditions. The use of variable porosity and volume due to shrinkage during drying improved notably the predictions of the simulation model. Written for presentation at the 2007 CIGR Section VI International Symposium on Food and Agricultural Products: Processing and Innovations, Naples, Italy, 24–26 September 2007.     

Antioxidant activity of polyphenol and anthocyanin extracts from fruits of Kadsura coccinea (Lem.) A.C. Smith

Polyphenols and anthocyanins were extracted from Kadsura coccinea fruit. The contents of total phenolics and anthocyanins, influences of pH and temperature on anthocyanins, and antioxidant activities of extracts were further analyzed. The results showed that the total phenolic content of peel extracts was superior to that of pulp extracts. The total anthocyanin content of peel extracts was 180 ± 2.91 mg/100 g of fresh peel tissues. K. coccinea anthocyanins were stable below pH 4, whilst high temperature and extended heating time induced their degradation. Metal-chelating capacity (MCC) assay indicated that no ortho-dihydroxy aromatic moiety existed in the B-ring of the anthocyanin molecules, but there might be a catechol group in the B-ring of the polyphenol molecules. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and reducing power of extracts decreased in the following order: peel polyphenol extracts > anthocyanin extracts > pulp polyphenol extracts. It would be worthwhile to introduce this rare fruit into more countries.     

In GC-MS, acrylamide from heated foods may be coeluted with 3-hydroxy propionitrile

Using the widely applied GC-MS method for direct analysis of acrylamide in heated foods, 3-hydroxy propionitrile (3-HPN) may be coeluted with acrylamide causing falsely high acrylamide values. Since it is often virtually the only peak in the gas chromatogram, such coelution is unexpected. 3-HPN was found in pears, apples, plums and tomatoes, independently of whether these were heated; in a sample of pears it quantitated as 2,800 μg/kg apparent acrylamide. Breakfast cereals, muesli and bakery ware with fruits may contain 3-HPN. The problem can be solved by tuning the chromatographic conditions to separate the two components or by a stationary phase other than the Carbowaxes usually used.     

果蔬叶绿素降解机理及护绿剂的研制

叶绿素的保绿是绿色蔬菜贮存与加工过程中的一大难题。本重点研究三种复合护绿剂的护色效果。结果表明,护绿剂攻护绿剂B效果不太明显,护绿剂C的护绿效果最好。