Orange sweet potato (OSP) and red rice (RR) are rich sources of health benefit-associated substances and can be conventionally cooked or developed into food products. This research approach was to closely monitor the changes of bioactive compounds and their ability as antioxidants from the native form to the food products which are ready to be consumed. Moreover, this research explored the individual carotenoids and tocopherols of raw and cooked OSP and RR and their developed flake products, and also investigated their antioxidant activity, physicochemical properties, and sensory properties. Simultaneous identification using the liquid chromatographic method showed that OSP, RR, and their flake products have significant amounts (µg/g) of β-carotene (278.58–48.83), α-carotene (19.57–15.66), β-cryptoxanthin (4.83–2.97), α-tocopherol (57.65–18.31), and also γ-tocopherol (40.11–12.15). Different responses were observed on the bioactive compound and antioxidant activity affected by heating process. Meanwhile, OSP and RR can be combined to form promising flake products, as shown from the physicochemical analysis such as moisture (5.71–4.25%) and dietary fiber (13.86–9.47%) contents, water absorption index (1.69–1.06), fracturability (8.48–2.27), crispness (3.9–1.5), and color. Those quality parameters were affected by the proportions of OSP and RR in the flake products. Moreover, the preference scores (n = 120 panelists) for the flakes ranged from slightly liked to indifferent. It can be concluded that OSP and RR are potential sources of bioactive compounds which could act as antioxidants and could be developed into flake products that meet the dietary and sensory needs of consumers.

Due to its important role, the use of antioxidant compounds has recently grown rapidly. Antioxidant compounds are known to be able to inhibit auto oxidation through radical scavenging mechanism, by donating one unpaired electron in free radical which leads to a reduced number of free radicals. In Indonesia there are many of medicinal plants that have active chemical compounds which are likely to be potential sources of antioxidants, which is neem (Azadirachta indica A. Juss). This plant has been widely used in various fields including natural pesticides (biopesticide) and natural medicine. The purpose of this research was to identify the active chemical compounds in neem leaves extracts and determine the antioxidant activity of neem leaves and the effective solvents in extracting active compounds of neem leaves. The materials used in this study were Neem leaves (Azadirachta indica A. Juss) from Yogyakarta. There were 5 types of solvents used, including: Ethyl acetate, Ethyl acetate-ethanol, Ethanol, Ethanol-water and Water. Neem leaves is a potential resources for natural antioxidant. In addition to obtaining highest yield using Ethanol-Water as a solvent during the extraction process, this solvent also results better characteristic of extract than 4 other solvents. The properties of the extract that produced by extraction using Ethanol-Water is 2.067 g GAE/g extract, yield 1.39%, flavonoid 0.326 mg QE/g extract, antioxidant activity 226.118 ppm and reducing power 0.778 g BHT/g extract. Therefore, it is recommended that Ethanol-Water as a solvent for the extraction of active compound on neem leaves.

Edible coating made from starch contributes to reducing oil uptake during processing. This research aimed to examine the effects of the edible coating application on the characteristics of potato chips prepared from the fresh tuber (PCT) and potato flour (PCF). The raw material for chipping was potato variety Granola. The edible coating was produced from sago starch, arrowroot starch, and tapioca. Edible coating from alginate was also examined. The coating was applied on the potato slices before frying. The parameters observed in this study were fat and moisture content, color parameter, and sensory properties that include crunchiness, a taste of potato, and preference. The results showed that the edible coating made from sago starch, arrowroot starch, and alginate reduced oil absorption of chips 3.90%, 8.29%, and 14.56%, respectively. There was no effect of edible coating found on the moisture content of chips. The L-, a-, and b-value indicate that the coated chips did not have a bright yellow color. All of the treated chips had L-value lower than 55. Most of the sensory properties of coated chips had a low hedonic score (less than 3) that were not preferred by the panelists. Whereas crunchiness and taste of chips made from the flour were still accepted by the panelists, the hedonic score was higher than 3.

Effect of Edible Coating on Quality of Chips from Potato Variety Granola

Potato is one of important agricultural commodities in Indonesia. The widely variety cultivated in Indonesia is Granola, almost 90 % of total area. The tuber is appropriate for table potato and not for processing one. On the other hand, the supply for processing tubers in Indonesia is less than its demand. Therefore, an alternative treatment is required for using variety Granola as raw material for processed product. Appropriate pretreatments are necessary to be applied to produce the flour from this variety. This research aims to examine the properties of potato flour as affected by several pretreatments during flour production from potato variety Granola. Potato tuber variety Granola was obtained from the farmers in Wonosobo, Central Java as one of potato producer in Indonesia. The pretreatments were type of soaking solution (water, solution of citric acid 2% and Lactic Acid Bacteria 0.1%) and type of blanching (without blanching, hot water blanching and steam blanching). Observed parameters were content of moisture, ash, starch, reducing sugar, and color parameter. The result indicates that combination of pretreatment using citric acid solution and steam blanching results better flours properties among others, particularly on the color parameter/brightness of the flour. The color of potato flour from variety Granola is yellow, which the bright color means more interesting for consumers. In addition, reducing sugars content of flour from this treatment is lower than control, but a disadvantage result also obtained from this treatment that is decreasing starch content of flour. Further research is required to improve flour properties to conform to the standard in Indonesia.