This study aims to determine the effect of solvent types on antioxidant activity of lemon peel (Citrus limon (Linn.) Burm F.) extract and to obtain the right solvent types with the highest antioxidant activity of lemon peel extract. The experimental design used in this research  was a completely randomized design with the treatment of solvent types (aquades, acetone 70%, ethanol 70% and methanol 70%). The treatment  was repeated four times to obtain 16 units of the experiment. Data were analyzed with analysis of variance (ANOVA) and followed by Duncan test. The result showed that the best treatment was obtained extract with ethanol 70% solvent with antioxidant activity was 52.72% and the IC50  value 471.33 mg/L, followed by yield was 37.68%, vitamin C was 227.90 mg AAE/g extract and total flavonoid was 7.14 mg QE/g extract.

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This research was conducted with the aim to know the influence of acid and solvent pH on the extraction of pectin from lemon peel and find the right kind of acid and solvent pH to produce pektin of lemon peel with the best characteristics. The experimental design used in this research was a factorial Completely Randomized Design (CRD), which consisted of two factors. The first factor was a type of acid consisting of chloride acid and citric acid. The second factor was a solvent pH consisting of a pH 1,5; 2; 2,5 and 3. All treatments were repeated twice to obtain 16 units of experiments. The data were analyzed with analysis of variance and followed by Duncan test. The best results showed that extraction using chloride acid and pH of solvent 1,5 resulted in 22,35% of pectin yield, 11, 55% of water content, 22,11% of ash content, 1052,47% of equivalent weight, 10,81% of methoxyl content, 78,07% of galacturonic content, and 78,58% of esterification degree.

This research was conducted to determine effect of the extraction time and ethanol concentration on antioxidant activity of corn silk extract and to obtain extraction time and ethanol concentration using Microwave Assisted Extraction (MAE) that can produce extract with the highest antioxidant activity. The experimental design used in this research was a completely randomize design, which consisted of two factors. The fisrt factor was the concentration of ethanol which consisted of 5 level that namely ethanol 30%, 45%, 60%, 75%, and 90%. The second factor was the time of extraction which consisted of 3 level namely 8, 13 and 18 minutes. Data were analyzed with analysis of variance that followed by Duncan test. The result showed that the best treatment of corn silk extract is extraction by ethanol 90% for 18 minutes using MAE which the highest resulted rendemen was 24.54%, total phenol was 159.65 mg GAE/g extract, total flavonoid was 149 mgQE/g extract, antioxidant activity was 70.18%, and the IC50 value 64.806 ppm.

Microemulsion is a dispersion system developed from emulsions, which is an oil dispersion system in water, stabilized by a surfactant. Oil-in-water (o/w) microemulsion is an emulsion system suitable for encapsulation and carrier of lipophilic components in the beverage industry. The food grade microemulsion formulation is limited by the type of surfactant that can be used. This research aims to obtain an o/w microemulsion formulation which is stable during storage using three surfactants. In this study, 3 types of food grade surfactants were used, Tween 80, Tween 20, and Span 80, and the oil used is Virgin Coconut Oil (VCO). This research is done in two stages. The first stage of research was the determination of the best microemulsion of 5 variations of HLB: 11, 12, 13, 14, and 15. The second stage is the storage stability test of the microemulsion chosen in the first stage for 7 weeks with observation every week. The data obtained were analyzed by ANOVA. The results of the study shows that HLB 11, 12, 13, 14, and 15 obtained by using 3 surfactants can produce microemulsions. The optimum HLB to obtain the best microemulsion stability is HLB 13. The microemulsion with HLB 13 obtained using 3 surfactants is stable during time of 7 weeks storage.