Development and quality evaluation of jelly coated cassava tapai as a cocktail product

The design process of cassava tapai products into cocktail products by heating with the high-temperature short-time method can extend the tapai’s shelf life. But this treatment cannot improve the brittle texture to a consistent solid to meet a cocktail’s requirements. This study aimed to design cassava tapai processed products with textures that meet the criteria to be made into cocktail cassava tapai. The coating of jelly on the cassava tapai is an alternative to design cocktail cassava tapai. Three kinds of jelly sources (grass jelly, carrageenan and gelatin) were experimented on, each in a single factor experiment arranged in separate completely randomised designs. Each treatment in each experiment was carried out with three replications. The grass jelly coating was processed from 200- 275 g of green grass jelly leaves per 100 mL of water, while carrageenan- and gelatincoating provided by carrageenan and gelatin concentration of 0-9 and 0-2.5%, respectively. Then selection of cassava tapai coatings then based on hedonic sensory responses to colour, texture, and taste. The data obtained were analysed using the Friedman test followed by the Dunn test. The treatment of the three jelly coatings affected significantly on the sensory properties (p<0.05) of cassava cocktail tapai for the total acceptance attribute. The grass jelly coated (200 g green grass jelly leaves per 100 mL), carrageenan coated (2.5%) and gelatin coated (7%) cassava tapai gave the best sensory acceptance of cocktail cassava tapai, each with a score (median) of 5, 6 and 6 (on a scale from 1-7 to strongly dislike to very much like), respectively. Based on the mean rank data, the 7% gelatin coated cassava tapai showed the highest hedonic response of total acceptance (p<0.05) among the three types of jelly coatings with a mean rank value of 3.14. In comparison, the other two jelly coating ingredients showed a mean rank of 2.98 and 2.93 for 2.5% carrageenan coated cassava tapai and 200 g/100 mL grass jelly coated cassava tapai, respectively. These results concluded that 7% gelatin coated cassava tapai is recommended as the cocktail cassava tapai.

Long-term carbon sink in Borneo's forests halted by drought and vulnerable to edge effects

Less than half of anthropogenic carbon dioxide emissions remain in the atmosphere. While carbon balance models imply large carbon uptake in tropical forests, direct on-the-ground observations are still lacking in Southeast Asia. Here, using long-term plot monitoring records of up to half a century, we find that intact forests in Borneo gained 0.43 Mg C ha⁻¹ per year (95% CI 0.14–0.72, mean period 1988–2010) in above-ground live biomass carbon. These results closely match those from African and Amazonian plot networks, suggesting that the world’s remaining intact tropical forests are now en masse out-of-equilibrium. Although both pan-tropical and long-term, the sink in remaining intact forests appears vulnerable to climate and land use changes. Across Borneo the 1997–1998 El Niño drought temporarily halted the carbon sink by increasing tree mortality, while fragmentation persistently offset the sink and turned many edge-affected forests into a carbon source to the atmosphere.

The existence of a pan-tropical forest carbon sink remains uncertain due to the lack of data from Asia. Here, using direct on-the-ground observations, the authors confirm remaining intact forests in Borneo have provided a long-term carbon sink, but carbon net gains are vulnerable to drought and edge effects.