Effect of Microwave Heating on Potato and Tapioca Starches in Water Suspension

The effects of microwave heating on properties of starch were studied on potato and tapioca starches in water suspension at different temperature (50°C and 60°C). Potato and tapioca starches were adjusted to 30% (w/v) and heat-moisture treated in a microwave oven and conventional heating.Conventional heating was carried out by direct heating the moisture heated sample at 50oC and 60oC while the microwave heating was carried out by microwave oven and the temperature was controlled approximately to 50oC and 60oC. The heated starch samples were analyzed for amylose content, pasting properties, swelling and solubility, thermal properties, light microscopy, scanning electron microscopy (SEM) and X-ray diffraction. There were present several changes on physicochemical and functional properties of heated starch for both heating methods. However, microwave method gave higher affect on heating treatment rather than conventional heating. Microwave heating was evidenced in affecting pasting properties of potato and tapioca starches by increase the pasting temperature and the paste stability. Microwave heating also significantly increased the amylose content and swelling power but reduced the solubility and enthalpy of gelatinization (ΔH) of those starches. There were changes in granule structure of starch observed by loss of birefringence and ruptures granule in SEM micrographs in both heating treatment. A change in the X-ray diffraction pattern from B-type to A-type was occurred in potato starch but tapioca starch shows no changes in X-ray pattern

PENGARUH TEKNIK PENGEKSTRAKAN TERHADAP KANDUNGAN FITOKIMIA DAN SENSORIS MINUMAN SIRIH MERAH

Sirih merupakan tanaman herbal yang dapat mengobati berbagai penyakit. Sirih Merah adalah jenis sirih yang banyak terdapat di Indonesia namun kurang diminati oleh masyarakat karena rasa getir dan aroma pahitnya. Tanaman ini mengandung fitokimia seperti flavonoid, phenolik, vitamin C dan antioksidan. Tujuan dari penelitian ini adalah untuk mengkaji pengaruh teknik ekstraksi terhadap kandungan fitokimia dan sensoris pada minuman sirih Merah (Piper crocatum). Parameter yang diamati adalah kandungan vitamin C, phenolik, flavonoid, antioksidan dan penilaian sensoris. Analisis sensoris dilakukan dengan menggunakan 7 skala Hedonik (sangat tidak suka – sangat suka) dengan 35 orang panelis. Hasil penelitian menunjukkan bahwa suhu ekstraksi mempengaruhi kandungan vitamin C, antioksidan pada sampel minuman sirih (72,89 – 98,78 ppm vitamin C), phenolik pada sampel sirih merah (160,56 ppm asam galat/ ml – 244,63 ppm asam galat/ ml). Penambahan asam gelugur pada minuman sirih dapat meningkatkan kandungan flavonoid sebesar 54.87 ppm catechin/ ml. Penambahan asam gelugur dapat meningkatkan penerimaan sensoris. Teknik ekstraksi mempengaruhi kandungan fitokimia dan penerimaan sensoris minuman sirih merah

Investigation on the effect of tea polyphenol extracts to digestion properties.

This research is conducted to determine antioxidant activity in different types of tea [black tea (8T), oolong tea (OT), green tea (GT), spent black tea (S8T), spent oolong tea (SOT) and spent green tea (SGT)] and to study the effect on polyphenols on digestion enzymes. Gallic acid, caffeine and four catechins (catechin, gallocatechin, epicatechin and epigallocatechin) were analyzed and quantified by using HPLC. Investigation on the hypoglycemic effect of those teas using suitable in vitro methods and developing biscuits incorporated with 8T and SST and to evaluate the effect on nutritional compositions, texture profile, color, sensorial acceptability and glycemic index (GI) value. GT obtained the highest TPC, TFC and antioxidant activity followed by oolong and black tea. The analytical HPLC results obtained also indicated that GT contained significantly higher amount of catechins than OT, 8T, SGT, SOT and SBT. However, BT showed significantly higher glucose adsorption capacity than S8T, and others samples and all samples exhibited significant reduction in glucose diffusion and amylolysis kinetics studies compared to control. 8T inhibited the highest alpha-amylase and apha-glucosidase activity in a dose dependent manner. From in vitro amylolysis kinetics, BT and SST incorporated biscuit found significantly reduced glucose release compared to control biscuit

Characterization of Probiotics from Water Kefir Grains

The probiotic potential of lactic acid bacteria (Lactobacillus mali, Lactobacillus casei, and Oenococcus oeni), acetic acid bacteria (Gluconobacter maltaceti), and yeast (Saccharomyces cerevisiae) strains isolated from water kefir (WK) grains were identified and evaluated. All five isolates were acid- and bile-salts tolerant. These strains appeared to be non-hemolytic, susceptible to antibiotics, adhered to porcine gastric mucin, and exhibited high antimicrobial activities against enteric pathogens. All identified five strains have in vitro probiotic properties. The detected genera in the WK grains used in this study included Lactobacillus, Lactococcus, Leuconostoc, Oenococcus, Acetobacter, and Gluconobacter

Phosphorylation of sago (Metroxylon sagu) starch cross-linked with sodium triphosphate and the physicochemical properties of the potential application in batter

This study evaluated the effect of sago starch cross-linked phosphorylated with sodium tripolyphosphate (STPP) (4%, 8%, and 12%) in fried batter. The 12% STPP produced cross-linked starch with the highest degree of substitution (DS) at 0.017. The swelling power, amylose content, peak viscosity, breakdown viscosity, and setback were reduced as the concentration of STPP increased. The oil uptake of the fried batter added with 20% of cross-linked sago starch with the highest DS (WFCLS12) was significantly reduced from 29.16% to 19.5%. The fracturability of the fried batter added with cross-linked sago starch showed significantly higher crispness (WFCLS4—883.45 g; WFCLS8—666.61 g; WFCLS12—499.89 g) than 100% wheat flour (WF—1094.60 g). It was demonstrated that STPP (especially WFCLS12) is an effective cross-linking agent, and the addition of cross-linked sago starch into wheat flour–based batter significantly (p < .05) improved the quality of the batter