No abstract

Oil was extracted from the seeds of white-flesh and red-flesh dragon fruits (Hylocereus spp.) using a cold extraction process with petroleum ether. The seeds contained significant amounts of oil (32-34 %). The main fatty acids were linoleic acid (C18:2, 45-55 %), oleic acid (C18:1, 19-24 %), palmitic acid (C16:0, 15-18 %) and stearic acid (C18:0, 7-8 %). The seed oils are interesting from a nutritional point of view as they contain a large amount of essential fatty acids, amounting to up to 56 %. In both dragon fruit seed oils, tri-unsaturated triacylglycerol (TAG) was mainly found while their TAG composition and relative percentage however varied considerably. Therefore, they showed a different melting profile. A significant amount of total tocopherols was observed (407-657 mg/kg) in which the a-tocopherol was the most abundant (*72 % of total tocopherol content). The impact of storage conditions, cold and room temperatures, on the oxidative stability and behavior of tocopherols was monitored over a 3-month storage period. During storage, the oxidative profile changed with a favorably low oxidation rate (*1 mequiv O 2 /week) whilst tocopherols decreased the most at room temperature. After 12 weeks, the total tocopherol content, however, still remained high (65-84 % compared to the initial oils). Hereto, the dragon fruit seed oils can be considered as a potential source of essential fatty acids and tocopherols, with a good oxidative resistance.

The pectic and hemicellulosic cell wall polysaccharides from the pulp and the peel of white-flesh and red-flesh dragon fruits (Hylocereus spp.) were isolated and compared in terms of degree of methoxylation (DM), solubility properties (relative content of uronic acids and neutral sugars in different fractions), neutral sugar composition, molar mass distribution, and affinity towards some specific anti-pectin antibodies. Hereto, the alcohol insoluble residues were extracted and sequentially fractionated using hot water, a chelating agent, sodium carbonate, and potassium hydroxide solutions to obtain different pectin fractions and a hemicellulose fraction. Chemical analyses were used to characterize these polysaccharide fractions. The results show that cell wall polysaccharides of the pulp and especially of the peel from white-flesh and red-flesh dragon fruits contain significant amounts of pectic substances that are lowly methyl-esterified. The cell wall polysaccharides of the peel as well as those of the pulp contain high amounts (38-47%) of loosely bound (water-soluble) pectic substances. In the water-soluble fraction (WSF) of the peel samples, uronic acids are the predominant monomers. On the contrary, rhamnogalacturonan-I type neutral sugars, and especially arabinose and galactose, contribute equally, as compared to uronic acid, to the WSF of the pulp samples. Despite the low average DM value of pulp and peel pectin, pectic substances in both samples showed affinity for antibodies with different specificities indicating that a wide range of epitopes, including long blocks of unesterified galacturonic acids (GalA) residues as well as (short) blocks of esterified GalA residues, are present. No large differences between the pectic substances among the different dragon fruit varieties were observed

The research aimed to study the effect of hot-air drying on the properties of edible bolete mushroom (Phlebopus colossus (R. Heim) Singer). Fresh edible bolete contained an efficient antioxidant activity, showing a significant value of total phenolic content and radical scavenging activity and was high in protein and fiber with low fat content. The changes in physicochemical and antioxidative properties of edible bolete during hot-air drying at various temperature and time were studied. The phenolic content and antioxidative properties of edible bolete decreased with the temperature and drying time. At 60 °C for 5 h, the phenolic content and antioxidative properties of the dried edible bolete remained at 25% compared to the fresh mushroom. Moreover, there was no substantive change in the bacterial count of dried edible bolete with vacuum packing after six months at room temperature.

Pandan (Pandanus amarylifolius) leaves have been used for culinary purposes and also for medicinal uses due to having the benefit of health promoting as a diuretic, cardio-tonic and anti-diabetic (Jimtaisong & Krisdaphong, 2016;Wakte et al., 2010). In addition, the pandan leaves consist of glycosides, amino acids and vitamins, and contain phytochemicals like steroids, phenols, isoflavones, coumestrol, lignans, alkaloids, terpenoids, flavonoids, and saponins