Physico-chemical properties of agar extracted from Gracilariopsis longissima (formerly Gracilaria verrucosa) and development of plant-based food jellies

• Gracilariopsis longissima (formerly G. verrucosa ) gave the highest agar yield from hot water extraction at 90 °C. • 1.5% (w/v) agar gel prepared using native agar powder extraction at 90 °C gave superior gelling properties. • Agar is used as a gelling agent in the food industry and there is a leading trend for gelatin-free food jellies. • Therefore, agar from Gracilariopsis longissima (formerly G. verrucosa ) can be used to develop plant-based food jellies instead of gelatine. In this study, agar was extracted from red seaweed, Gracilariopsis longissima (formerly G. verrucosa ) by hot water extraction, and the physicochemical and gelling properties of the extracted agar were examined. Furthermore, attempts were made to develop plant-based food jellies and compare them with gelatine-added jellies. The moisture, total lipid, total carbohydrate, total ash, and crude fiber content of the dried Gracilariopsis longissima (formerly G. verrucosa ) were 6.55±0.01%, 1.63±0.04%, 6.09±0.29%, 4.88±0.26%, and 12.41±0.57%, respectively. Extraction of agar was conducted under three different temperatures such as 50 °C, 70 °C, and 90 °C and the highest dried agar powder yield was gained at 90 °C. Further, the highest melting temperature, gelling temperature, and pH were displayed by agar gel prepared using agar powder extracted at 90 °C and values were 60.33±1.53 °C, 37.00±1.00 °C, and 6.23±0.03, respectively. Moreover, plant-based food jellies were developed with 4, 8, and 12 g of agar extracted from Gracilariopsis longissima (formerly G. verrucosa ) instead of gelatine. According to the sensory evaluation results, the highest preference was achieved by 12 g agar-added jellies. In conclusion, agar from Gracilariopsis longissima (formerly G. verrucosa ) is an alternative plant-based gelling agent that can be used in the manufacture of food jellies.