Among natural pigments, carotenoids play important roles in physiological functions. The characteristics of carotenoids and their effects on human health have been reported for a long time, but most studies have focused on carotenoids from vegetables, fruits, and other parts of higher plants. Few reports are available on carotenoids from marine sources, such as seaweeds, microalgae, and marine animals, which have attracted attention in recent decades. Hundreds of carotenoids have been identified and isolated from marine organisms and their beneficial physiological functions, such as anticancer, antiobesity, antidiabetic, anti-inflammatory, and cardioprotective activities have been reported. The purpose of this review is to discuss the literature on the beneficial bioactivities of some of the most abundant marine carotenoids, including fucoxanthin, astaxanthin, cantaxanthin, peridinin, fucoxanthinol, and halocynthiaxanthin.

Gac (Momordica cochinchinensis Spreng.) is a tropical vine originating from South and South-East Asia. Gac fruit has traditionally been used in Asia to provide red colour for cuisines and enhance visional health. Recently, Gac fruit has emerged as a potential source of carotenoids, especially lycopene and b-carotene. Carotenoids and other identified bioactives from this fruit including phenolics, flavonoids and trypsin inhibitors are associated with many beneficial bioactivities such as antioxidant, anticancer and provitamin A activities. In addition to the traditional utilisation, commercial products like Gac powder and Gac oil have been manufactured as natural colourants and medicinal supplements. This paper is a review of the scientific literature on the nutritional composition, biological activities and processing of Gac fruit.

The peel of Gac fruit (Momordica cochinchinensis Spreng.) contains high levels of bioactive compounds, especially carotenoids which possess significant antioxidant capacities. However, the peel of Gac is regarded as a waste from the production of carotenoid‐rich oil from Gac fruit. In this study, carotenoids of Gac peel were extracted by microwave‐assisted extraction (MAE) and ultrasound‐assisted extraction (UAE) using ethyl acetate as extraction solvent. The effect of extraction time and different levels of microwave and ultrasonic powers on the yield of total carotenoid and antioxidant capacity of the extracts were investigated. The results showed that an extraction at 120 W for 25 min and an extraction at 200 W for 80 min were the most effective for MAE and UAE of the Gac peel samples, respectively. The maximum carotenoid and antioxidant capacity yields of UAE were significantly higher than those of the MAE. The antioxidant capacity of extract obtained by the UAE was also significantly higher that of the conventional extraction using the same ratio of solvent to material. The results showed that both MAE and UAE could be used to reduce the extraction time significantly in comparison with conventional extraction of Gac peel while still obtained good extraction efficiencies. Thus, MAE and UAE are recommended for the improvement of carotenoid and antioxidant capacity extraction from Gac peel.