PREDIKSI KADAR PATI UBI KAYU (Manihot esculenta) PADA BERBAGAI UMUR PANEN MENGGUNAKAN PENETROMETER

Over the years, determination of starch content by the buyers on the field is performed based on the difference between cassava’s weight on the air and that of in the water, then counted based on the formula designed by International Starch Institute (ISI). This method has been proven to be highly correlated with the starch content determined chemically such as acid hydrolysis. However, this method is less practical due to the need of a large amount of water which is rarely found on cassava plantation. The aims of this study were : 1) to find alternative way to measure cassava’s starch content on the field using penetrometer, 2) to find correlation between starch content measurement using penetrometer and weighing method as described by ISI; correlation between hardness measured using penetrometer and acid hydrolysis. The experiment was arranged as a single treatment harvesting period consisted of 7, 8, 9 and 10 month in a complete randomized  design  with three replications. Data were analyzed using linier regression to find correlation between hardness and starch content analyzed using acid hydrolysis ; correlation between starch yield and starch content analyzed using acid hydrolysis; correlation of starch content analyzed using acid hydrolysis and that of using ISI method. The result shows that there is a high positive correlation between cassava’s hardness using penetrometer and cassava’s starch content using acid hydrolysis method. This implies that penetrometer is a potential tool for predicting cassava’s starch content. Keywords : cassava, penetrometer, hardness, starch conten

KARAKTERISTIK FUNGSIONAL POLISAKARIDA PEMBENTUK GEL DAUN CINCAU HIJAU (Premna Oblongifolia Merr.)

The effect of citric acid concentration on functional characteristics of polysaccharide forming gel (PFG) of green cincau leaves (Premna Oblongifolia Merr.) were evaluated. PFG of green cincau leaves were extracted through the use of citric acid (0,0%, 0,1%, 0,2%, 0,3%, 0,4%, and 0,5% w/v) solution, precipitated using ethanol, and  followed by drying of the extracts.  The results showed that increasing of citric acid levels reduced the viscosity, water holding capacity, and bulking capacity of the PFGs. Oil holding capacity and water solubility were not affected by citric acid addition. The addition of 0.0% citric acid produced the highest viscosity, water holding capacity, and bulking capacity suggesting possible uses of the extract as dietary fibre with good laxative effect.   Key Words:  Green cincau leaves, functional characteristic, dietary fibre

KAJIAN AKTIVITAS ANTIBAKTERI PRODUK ETANOLISIS DARI CAMPURAN MINYAK INTI SAWIT (Elaeis quineensis Jacq.) DAN MINYAK BIJI MENGKUDU (Morinda citrifolia L.)

The objective of this research was to measure antibacterial activities of ethanolysis products that produced through ethanolysis reaction of mixture of palm kernel oil (PKO) and Morinda seeds oil (25:1 and 50:1, w/w) in ethanol solution contained 1% NaOH (v/w based on oil weight) at ratio of 5 : 6 (b/v) and shaken on a shaker (300 rpm, room temp.) for 3, 6, 9 and 12 minutes. Fractionation of ethanolysis products using absolute ethanol (1:3; v/v) and centrifuged at 4.000 rpm for 30 min, yielding Fraction 1 (upper layer) and Fraction 2 (lower layer).  Generally, all ethanolysis products showed antibacterial activities against four test bacteria (E. coli, S. aureus, B. cereus and S. enteritidis) at range of d values (mm) from 0,93 (B. cereus; 3 min) up to 3,87 (E. coli; 9 min). Fraction 1 showed the highest antibacterial activity with d values (mm) from 1,20 (B. cereus; 9 min) up to 5,63 (E. coli; 9 min), while Fraction 2 for all treatments had no antibacterial activity, relativelly.  Ethanolysis products and its fraction (Fraction 1) were resulted from ethanolysis reaction for 6 and 9 min showed higher antibacterial activities than those for 3 and 12 min. Keywords: Antibacterial activities, ethanolysis product, Morinda seeds oil, PKO

PENGOLAHAN DURIAN (Durio zibethinus) FERMENTASI (TEMPOYAK)

Tempoyak is fermented durian that is popular as a side dish and condiment prepared by placing durian pulp in jars to which salt is added, carefully mixed and tightly closed and kept for seven to ten days to let fermentation take place. Based on salt content, tempoyak can be categorized as tempoyak with low salt content (less than 5%) that result in sour tempoyak and tempoyak that has high salt content more than 5% (salty tempoyak). Law salt content is more favor for lactic acid bacteria (LAB) growth so the final acidity of tempoyak is higher than those with hight salt content. Durian fermentation process can be carried out trhough spontaneous fermentation or in under controlled fermentation with LAB starter addition, wet or dry starter. This last mean will shorthen the fermentation length to be 2-4 days with better microbiology quality.  Tempoyak inoculated with wet starter has caharecterisitc watery concistency. Mean while, dry Pediococcus acidilactici application give tempoyak with more prefered sensory, less watery consistency and less acid taste as well as easier fermentation control. However, its adaptation time is longer than that in wet starter application. To enhance the sensory, some cane sugar can be added before tempoyak being fermented and the level of sugar added should consider the balance of the sour taste and sweet sensory of the final tempoyak. Keywords : pengolahan tempoyak, kultur cair, kultur kering, tempoyak asam dan tempoyak asin