Effect of solvent pre-treatment on the physicochemical, thermal profiles and morphological behavior of Mangifera pajang seed fat

In this work, the effect of solvent pre-treatment (hexane, petroleum ether and ethanol) on the physicochemical, thermal and morphology behavior of Mangifera pajang seed fat (MPSF) were investigated. Fat extraction was performed using Soxhlet method, and results showed that the yield, physicochemical, and crystalline structures of the MPSF were significantly (p < 0.05) influenced by the extraction solvents. Hexane gave the highest fat yield (7.67 %) with low unsaturation value (52.13 g iodine/g) compared with petroleum ether and ethanol. Hexane MPSF also had low oxidation rate (peroxide value of 1.1 mEq/g). Both non-stabilized and stabilized hexane MPSF showed a single melting endothermic peak at high temperature with onset, maximum peak and offset temperature of 16.23 ˚C-18.21 °C, 28.22 ˚C-31.25 °C and 34.85 ˚C-39.58 °C, respectively. Hexane MPSF crystallized rapidly at high temperature with single maximum peak starting at 16.51 ˚C-16.68 °C and ending at 0.23 ˚C-1.13 °C. In comparison with ethanol extract, hexane MPSF demonstrated a compact crystalline structure with a large densely packed center. Therefore, MPSF obtained from hexane presented better overall quality than those obtained from other extraction solvents. MPSF exhibited similar melting and morphological behavior to mango kernel fat and commercial cocoa butter. These results suggested that hexane was the best solvent for the extraction of MPSF. This fat also has the potential to be applied as a cocoa butter alternative fat or functional fat.

Effects of drying methods on oxidative stability of roselle seed oil (Hibiscus Sabdariffa): an optimization approach

The objective of this study was to optimize the extraction of oil from pre-dried roselle seeds using response surface methodology (RSM). We also determined the oxidative stability of oil extracted from oven and freeze-dried roselle seed in terms of iodine value (IV), free fatty acid (FFA) value, peroxide value (PV), P-anisidine and total oxidation values (TOTOX value). The RSM was designated based on the central composite design with the usage of three optimum parameters ranged from 8 to 16 g of sample weight, 250-350 mL of solvent volume, and 6-8 h of extraction time. The highest oil yielded from roselle seed using the optimization process was 22.11% with the parameters at sample weight of 14.4 g, solvent volume of 329.70 mL, and extraction time of 7.6 h. Besides, the oil extracted from the oven dried roselle seed had the values of 89.04, 2.11, 4.13, 3.76 and 12.03 for IV, FFA, PV, P-anisidine, and TOTOX values, respectively. While for the oil extracted from freeze-dried roselle seed showed IV of 90.31, FFA of 1.64, PV of 2.47, P-anisidine value of 3.48, and TOTOX value of 8.42. PV and TOTOX values showed significant differences whereas; IV, FFA, and P-anisidine values showed no significant differences between the oven and freeze-dried roselle seed oils.

Effect of various food processing and handling methods on preservation of natural antioxidants in fruits and vegetables

Bioactive compounds from plant sources are generally categorized as natural antioxidants with well-known health benefits. The health-promoting characteristics of natural antioxidants include anti-inflammatory, anti-diabetic, and hepatic effects as well as free radical scavenging. Herein, a comprehensive and comparative review are presented about the effects of conventional (thermal and mechanical) and relatively new (non-thermal) processing methods on phytochemicals and discussed the importance of implementing the use of those methods that could be of very helpful retaining the quality of the bioactive compounds in plant-based foods. Plant-based foods rich in phenolics, vitamin C, carotenoids, and other compounds undergo a range of processing operations before they are consumed. Most of these methods involve thermal treatments of fruits, stems, leaves, and roots. These techniques have varying effects on bioactive compounds and their activities, and the magnitude of these effects depends on process parameters such as temperature, time, and the food matrix. Thermal processing can be detrimental to bioactive compounds while nonthermal procedures may not cause significant deterioration of important health-promoting phytochemicals and in some cases can improve their bio-activity and bio-availability. The detrimental effects of conventional processing on the quality of natural antioxidants have been compared to the effects of innovative nonthermal food treatments such as gamma and ultraviolet irradiation, ultraviolet light, pulsed electric fields, and high hydrostatic pressure.

Beneficial roles of honey polyphenols against some human degenerative diseases: A review

Honey contains many active constituents and antioxidants such as polyphenols. Polyphenols are phytochemicals, a generic term for the several thousand plant-based molecules with antioxidant properties. Many in vitro studies in human cell cultures as well as many animal studies confirm the protective effect of polyphenols on a number of diseases such as cardiovascular diseases (CVD), diabetes, cancer, neurodegenerative diseases, pulmonary diseases, liver diseases and so on. Nevertheless, it is challenging to identify the specific biological mechanism underlying individual polyphenols and to determine how polyphenols impact human health. To date, several studies have attempted to elucidate the molecular pathway for specific polyphenols acting against particular diseases. In this review, we report on the various polyphenols present in different types of honey according to their classification, source, and specific functions and discuss several of the honey polyphenols with the most therapeutic potential to exert an effect on the various pathologies of some major diseases including CVD, diabetes, cancer, and neurodegenerative diseases.