Sulawesi endemic tubers and perimedular flour properties an initial consideration for alternative sources for food starch ingredient

Abstract

North Sulawesi is located in the North-Eastern regions of the Indonesian Archipelago. As it is with most parts of Indonesia, North Sulawesi is dependent on rice as their staple food. Not all islands within the North Sulawesi cluster of islands can grow paddy or corn for their carbohydrate needs or starch ingredients in their diet and must have them shipped from other places with the dire consequences of transportation costs. The endemic biodiversity of these islands also has many plants with the potential as an alternative food carbohydrate source. This study was to explore these endemic plants for potential food ingredients for starch replacements for rice and corn. The many diversities available for these starch ingredients amongst them are tuber sources (Taro – Colocasia esculenta, Dalugha – Cyrtosperma merkusii, Gembili – Discorea esculenta and Banggai – Discorea alata) and perimedular sources (Sago Tanah and Sago Baruk). Many studies have researched these plants individually in various originating from many other parts of the world, but not many have made a head-to-head comparison and explored the potentials of these underutilized plants as starch food ingredients. This study extracted starches of these plants in a standardized manner and compared the properties side-by-side. These plants were found to be potentially healthy alternatives to rice as functional food starch with lower digestibility which would lead to lower GI staples, especially for the livelihoods of North Sulawesi coastal dwellers.

Effect of Acid Modification on the Physico-Chemical Properties of North Sulawesi’s Giant Swamp Taro (GST) Starch (Cyrtosperma merkusii)

“…Native GST has been found to have high carbohydrates content of 89.58% in which 68.43% of it is total starch. 2 Out of the 68.43% total starch content, GST had 15.58% amylose and 52.86% amylopectin. 2 The acid hydrolysis of the GST starch has considerably reduced the total starch content to 46.86 ± 1.34% with an amylose content of 13.02 ± 0.22% and 33.84 ± 1.12% amylopectin.…”

“…The dried starch sediments were then crushed using a disc miller. 4 Starch Modification GST starch was modified by acid hydrolysis according to the method previously described. 30 GST starch was suspended in water and heated in an autoclave at 121°C for 30 min and then cooled at 4°C for 24 h. The starch suspension was diluted in 0.2 M citric acid solution (10%, w/v) then incubated at 45°C for 24 h, the starch was then neutralized by the addition of 1 M NaOH until the pH became 7.…”

“…GST are potential staple food material with a high carbohydrate composition (81-83%), with a starch content of 65.52 ± 0.02%, amylose and amylopectin composition of 29.63 ± 0.01% and 32.88 ± 0.02%, respectively and crude fibre of 18.55%. 2 GST is also a healthy food source with a resistant starch composition of 11.37 ± 0.03% and digestive starch content of 44.30 ± 0.26%, which is a healthier digestive character in processed foods by reducing carbohydrate loading and conversion into blood sugar and therefore has the potential as functional foods with low glycaemic index. 2,3 GST starch can be developed into advanced food products like dried noodles.…”

“…2 GST is also a healthy food source with a resistant starch composition of 11.37 ± 0.03% and digestive starch content of 44.30 ± 0.26%, which is a healthier digestive character in processed foods by reducing carbohydrate loading and conversion into blood sugar and therefore has the potential as functional foods with low glycaemic index. 2,3 GST starch can be developed into advanced food products like dried noodles. 4 The pulp biomass or waste from GST starch processing contains various important components such as fibers, carbohydrates, ash, proteins, lignins, cellulose and hemicellulose which are a good source of cellulose nanocrystal (CNC) material.…”

“…2,3 GST starch can be developed into advanced food products like dried noodles. 4 The pulp biomass or waste from GST starch processing contains various important components such as fibers, carbohydrates, ash, proteins, lignins, cellulose and hemicellulose which are a good source of cellulose nanocrystal (CNC) material. 5 Waste biomass of GST starch processing are good sources of carbon and inorganic nitrogen that may serve as natural feed source for fisheries to increase tilapia survival rate and a feed source that can reduce blood glucose levels in broiler chickens.…”