Different bioactive flavonoid compounds including catechin, epicatechin, rutin, myricetin, luteolin, apigenin and naringenin were obtained from spearmint (Mentha spicata L.) leaves by using conventional soxhlet extraction (CSE) and supercritical carbon dioxide (SC-CO2) extraction at different extraction schemes and parameters. The effect of different parameters such as temperature (40, 50 and 60 °C), pressure (100, 200 and 300 bar) and dynamic extraction time (30, 60 and 90 min) on the supercritical carbon dioxide (SC-CO2) extraction of spearmint flavonoids was investigated using full factorial arrangement in a completely randomized design (CRD). The extracts of spearmint leaves obtained by CSE and optimal SC-CO2 extraction conditions were further analyzed by high performance liquid chromatography (HPLC) to identify and quantify major bioactive flavonoid compounds profile. Comparable results were obtained by optimum SC-CO2 extraction condition (60 °C, 200 bar, 60 min) and 70% ethanol soxhlet extraction. As revealed by the results, soxhlet extraction had a higher crude extract yield (257.67 mg/g) comparing to the SC-CO2 extraction (60.57 mg/g). Supercritical carbon dioxide extract (optimum condition) was found to have more main flavonoid compounds (seven bioactive flavonoids) with high concentration comparing to the 70% ethanol soxhlet extraction (five bioactive flavonoids). Therefore, SC-CO2 extraction is considered as an alternative process compared to the CSE for obtaining the bioactive flavonoid compounds with high concentration from spearmint leaves.

In this study, antibacterial characteristic of silver/poly (lactic acid) nanocomposite (Ag/PLA-NC) films was investigated, while silver nanoparticles (Ag-NPs) were synthesized into biodegradable PLA via chemical reduction method in diphase solvent. Silver nitrate and sodium borohydride were respectively used as a silver precursor and reducing agent in the PLA, which acted as a polymeric matrix and stabilizer. Meanwhile, the properties of Ag/PLA-NCs were studied as a function of the Ag-NP weight percentages (8, 16, and 32 wt% respectively), in relation to the use of PLA. The morphology of the Ag/PLA-NC films and the distribution of the Ag-NPs were also characterized. The silver ions released from the Ag/PLA-NC films and their antibacterial activities were scrutinized. The antibacterial activities of the Ag/PLA-NC films were examined against Gram-negative bacteria (Escherichia coli and Vibrio parahaemolyticus) and Gram-positive bacteria (Staphylococcus aureus) by diffusion method using Muller–Hinton agar. The results indicated that Ag/PLA-NC films possessed a strong antibacterial activity with the increase in the percentage of Ag-NPs in the PLA. Thus, Ag/PLA-NC films can be used as an antibacterial scaffold for tissue engineering and medical application.

Hylocereus undatus and Hylocereus polyrhizus are two varieties of the commonly called pitaya fruits. The seeds were separated and the oil was extracted and analysed. Essential fatty acids, namely, linoleic acid and linolenic acid form a significant percentage of the unsaturated fatty acids of the seed oil extract. Both pitaya varieties exhibit two oleic acid isomers. Essential fatty acids are important acids that are necessary substrates in animal metabolism and cannot be synthesised in vivo. Both pitaya varieties contain about 50% essential fatty acids (C18:2 (48%) and C18:3 (1.5%)). This paper details the process of recovering the pitaya seeds and determining the composition of the oil extracted from the seeds.

Recent rapid growth of the world's population has increased food demands. This phenomenon poses a great challenge for food manufacturers in maximizing the existing food or plant resources. Nowadays, the recovery of health benefit bioactive compounds from fruit wastes is a research trend not only to help minimize the waste burden, but also to meet the intensive demand from the public for phenolic compounds which are believed to have protective effects against chronic diseases. This review is focused on polyphenolic compounds recovery from tropical fruit wastes and its current trend of utilization. The tropical fruit wastes include in discussion are durian (Durio zibethinus), mangosteen (Garcinia mangostana L.), rambutan (Nephelium lappaceum), mango (Mangifera indica L.), jackfruit (Artocarpus heterophyllus), papaya (Carica papaya), passion fruit (Passiflora edulis), dragon fruit (Hylocereus spp), and pineapple (Ananas comosus). Highlights of bioactive compounds in different parts of a tropical fruit are targeted primarily for food industries as pragmatic references to create novel innovative health enhancement food products. This information is intended to inspire further research ideas in areas that are still under-explored and for food processing manufacturers who would like to minimize wastes as the norm of present day industry (design) objective.

Foam mat drying is an economical process compared to drum drying, spray drying, and freeze drying for the production of fruit powders. The aim of this study was to determine the effect of foaming agent concentration and whipping time on pineapple powder properties. Pineapple juice was foamed using egg albumen (EA) at different concentrations (5, 10, and 20%, wt/wt) and whipping time (10, 20, and 30 min). Physicochemical properties such as water absorption index, water solubility index, total phenolic content, total soluble solid, pH, color, water activity, moisture content, bulk density, hygroscopicity, and rehydration ratio were evaluated. As the concentration of foaming agent increases at constant whipping time, foam density was reduced and foam expansion was increased. The results indicated that foaming properties and physicochemical properties of powder were significantly affected by the whipping time (p < .05) and EA concentration (p ≤ .05). Practical applications Pineapple (Ananas comosus) is a tropical fruit and popularly consumed in the world. However, the shelf life of pineapple is limited. Foam mat drying is an alternative for the preservation of pineapple in the form of dried powder using moderate temperatures. Pineapple powder has found its application in various industries such as food processing and pharmaceuticals. It is widely used as flavoring agent in instant beverages, bakery products, pastes, frozen confectionaries, and as a component in pharmaceutical tablets. It is commonly utilized owing to its ability to provide distinguished properties of pineapple in terms of aroma, color, and flavor as well as water‐binding properties to the end product.

The bioactive flavonoid compounds of Strobilanthes crispus (Pecah Kaca) leaves obtained by using supercritical carbon dioxide (SC-CO2) extraction were investigated and the obtained crude extract yields were compared in order to select the best operation parameters. Since carbon dioxide is a non-polar solvent, ethanol was used as co-solvent to increase the polarity of the fluid. The studied parameters were pressure (100, 150 and 200 bar), temperature (40, 50 and 60 °C) and dynamic extraction time (40, 60 and 80 min). The optimum extraction condition occurred at 200 bar, 50 °C and 60 min. Based on the mean value, pressure had dominant effect on the extraction yield. Apart from the optimum SFE conditions two other conditions namely at minimum (100 bar, 40 °C, 40 min) and maximum (200 bar, 60 °C, 80 min) levels of each studied parameters as control runs were analyzed by HPLC to determine the major bioactive flavonoid compounds from S. crispus. Under the optimum conditions eight flavonoid compounds were identified; they were (+)-catechin, (−)-epicatechin, rutin, myricetin, luteolin, apigenin, naringenin and kaempferol.

In the present study, ultrasound-assisted extraction of crude oil from winter melon seeds was investigated through response surface methodology (RSM). Process variables were power level (25–75%), temperature (45–55 °C) and sonication time (20–40 min). It was found that all process variables have significant (p < 0.05) effects on the response variable. A central composite design (CCD) was used to determine the optimum process conditions. Optimal conditions were identified as 65% power level, 52 °C temperature and 36 min sonication time for maximum crude yield (108.62 mg-extract/g-dried matter). The antioxidant activity, total phenolic content and fatty acid composition of extract obtained under optimized conditions were determined and compared with those of oil obtained by the Soxhlet method. It was found that crude extract yield (CEY) of ultrasound-assisted extraction was lower than that of the Soxhlet method, whereas antioxidant activity and total phenolic content of the extract obtained by ultrasound-assisted extraction were clearly higher than those of the Soxhlet extract. Furthermore, both extracts were rich in unsaturated fatty acids. The major fatty acids of the both extracts were linoleic acid and oleic acid.

Headspace solid phase microextraction (SPME) coupled to fast gas chromatography-mass spectrometry (GC-MS) was applied to analyze the volatile compounds of durian (Durio zibethinus) varieties D2, D24, and D101 from Malaysia. Sampling sensitivity was improved by evaluation of sample matrix, sampling size, headspace volume, salt addition and sampling duration. A total of 39 volatile compounds were identified including 22 esters, 9 sulphur-containing alkanes, 3 thioacetals, 2 thioesters, 2 thiolanes and 1 alcohol. The relative amount of volatiles estimated using 1 ppm internal standard (IS) revealed the differences in the volatile composition among varieties. Further classification and characterization of each durian variety was successfully conducted using principal component analysis (PCA).