THE CHARACTERISTICS OF SAGO FROND SAP FROM TWO SELECTED GROWTH STAGES; ANGKAT PUNGGUNG AND UPONG MUDA PALMS

Sago frond is produced in abundance upon harvesting of the sago palms for starch extraction, hence need to be utilized and developed into beneficial products. In this study, the sap which contains sugars and starch is obtained by roller crushing the skinned frond for use as fermentation medium. Fronds from different growth stages (namely Angkat punggung and Upong muda) and different positions within the rosette (inner and outer circle) of the sago palm were studied. Based on the results, the outer circle frond of Upong muda palm gave the highest volume of sap at 290mL/kg which equivalent to 1600 mL/frond. On top of that, sago frond sap has an acidic pH, with glucose as major sugar component and contained various kinds of minerals like calcium, potassium and manganese. All fronds from different growth stages contain glucose between 28-68 g/L and xylose 21-29 g/L, respectively. After 21 days of storage, it can be concluded that the amount of reducing sugars and starch in all samples obtained from different growth stages remained almost unchanged from the original. Subsequently after this study, both fresh and stored sago frond sap can be used as a fermentation substrate without any modification.

Produksi dan Pemurnian Xilooligosakarida dari Xilan Tongkol Jagung menggunakan Xilanase Streptomyces P26B4 dan Khamir IP4

Xylooligosaccharides (XOS) are sugar oligomers from xylan that can be used as prebiotics to improve digestive tract health. Xylan can be extracted from corncobs which are a by-product of agriculture. The purpose of this study was to produce XOS through hydrolysis of corn cobs xylan using Streptomyces P26B4 xylanase. The products of hydrolysis also consisted of monomer xylose; for that xilooligosaccharides were purified using yeast IP4. The xylan hydrolysis products are quantitatively analyzed based on the value of reducing sugars and degree of polymerization (DP), strengthened qualitatively with TLC. Sugar component was analyzed after the addition of yeast by HPLC. P26B4 xylanase isolates had the highest activity on the 7th day incubation, pH 5,5 buffer citrate and temperature of 50°C. The lowest DP value of xylan hydrolysis was 2.49 at a concentration of 6%, and the 24th hour of incubation. TLC chromatograms showed that xylose and XOS products were produced. Purification of XOS at 6%, showed a decreasing in the area of xylose before and after receiving yeast respectively 1.87% and 1.41%.Therefore, yeast IP4 has the potential to consume xylose amnd purify the XOS. Keywords: corncobs xylan, IP4 yeast, purification, Streptomyces P26B4 xylanase, xylooligosaccharides

Apple Preload Halved the Postprandial Glycaemic Response of Rice Meal in Healthy Subjects

This study aimed to investigate the possible glycemic effect of apple preload on acute postprandial glycemic responses (GRs) of a following rice meal, comparing with its co-ingestion counterpart and an apple sugar solution preload, based on equal carbohydrates intake. In a randomized crossover trial, 18 healthy female subjects consumed (1) rice, (2) co-ingestion of apple and rice (A+R), (3) apple preload and rice (PA+R), and (4) rice with sugar solution preload (same sugar profile as in apple) (PSS+R). Acute postprandial GR tests and subjective satiety tests were carried out for each test food. Compared with rice reference, the PA+R achieved a 50% reduction of the iAUC0-120, a 51.4% reduction of the average peak value, and a 52.6% reduction of glycemic excursion in 240 min, while the PSS+R showed 29.7% and 31.6% reduction of peak value and glycemic excursion, respectively. No significant differences were found between R and PA+R in any of the satiety characteristics. Compared with rice control, apple preload of 15 g available carbohydrates remarkably lowered the acute postprandial GR without negative effect on satiety. The sugar component may partly contribute to the glycemic suppressing effect of the apple preload.

Influence of sugars and osmoregulators on motility and viability of cooled and frozen-thawed ram semen

The aim of the study was to determine the effect of sugars and osmoregulators on the viability of frozen-thawed ram semen in a Tris-based diluent. Two experiments were conducted to evaluate the effect of sugars (fructose, glucose, sucrose and raffinose) and two osmoregulators (hypotaurine and taurine) on the viability of ram sperm. In experiment 1, each of the four sugars (fructose, glucose, sucrose and raffinose) was added (500 mg%) to the diluents. Semen was collected from 15 rams once a week using an artificial vagina, diluted, cooled slowly to 5°C over 2 h, frozen in the form of pellets, and plunged into liquid nitrogen. The frozen semen was thawed, and sperm viability was calculated 3 h after thawing. In experiment 2, two osmoregulators, hypotaurine (0.20 and 0.40 mg/ml) and taurine (2 and 4 mg/ml), were added to Tris-based raffinose diluent. Motility and viability rates were calculated. The results showed that motility was gradually significantly (P < 0.05) improved by using 500 mg% raffinose in the Tris-based diluents after dilution at 30°C and before freezing at 5°C. Post-thawing motility and viability rates were highest (P<0.05) when raffinose was used in Tris-based diluent for cryopreservation of ram semen. In vitro supplementation of the semen diluent with 4 mg/ml taurine had a beneficial effect on the motility and viability of ram spermatozoa after dilution at 30°C and before freezing at 5°C. The same trend was observed after freezing-thawing and 3 h post-thawing. In conclusion, 500 mg% raffinose was a more suitable sugar component for treatment of ram spermatozoa in Tris diluent than fructose or glucose, while 4 mg/ml of taurine in Tris-raffinose medium exerted a beneficial effect on the motility and viability of ram sperm at cooling and post-thawing.