No abstract

The effects of partial renneting at low temperature on the casein micelle (CM) size and the storage stability of milk were investigated. Low chymosin concentrations (<0.03 IMCU mL-1) was applied to pasteurised skim milk at 4 o C and enzyme activity was terminated by thermal application at 60 o C/3 min and 85 o C/30 min, referred to as low heat (LHT) and high heat (HHT) treatment milk, respectively. The addition of rennet with concentrations of 0.01, 0.02 and 0.03 IMCU mL-1 for 15 minutes resulted in κ-casein hydrolysis of 10, 20 and 25%, respectively. Moreover, mean CM size of milk was reduced by up to 10 nm. For LHT milk, the renneted micelles appeared to be stable for up to 17 days, especially in response to the application of 0.01 IMCU mL-1 and at a storage temperature of 4 o C. Severe heating at 85 o C/30 min to inactivate the enzyme caused an increase in CM size.

Acid-and rennet-induced gelation properties of milk with modified casein micelles, produced by partial renneting at 4 o C for 15 min, followed by inactivation of enzymes by heat at 60 o C/3 min (referred as low heat treatment milk) and 85 o C/30 min (high heat treatment milk), were investigated to provide a mechanistic understanding of gel formation from partially renneted milk. Acidification of low heat treatment milk gave firmer gel quality, this was reflected by its high elastic modulus (G′) and hardness. In addition, the high heating condition for enzyme inactivation of high heat treatment milk alone increased the elastic modulus of both the control and renneted milk samples. Gel development of the two milk types (low heat treatment and high heat treatment milks) was different. In contrast with acid gelation, rennet-induced gelation of partially pre-rennet treated milk had no impact on the elastic modulus of low heat treatment milk and the rennet gels were very weak. Similarly, the addition of rennet to pre-rennet treated high heat treatment milk did not produce "true gels," most likely due to the effect of the heat treatment on impairing the rennet coagulation. The findings in this study confirmed that pre-rennet treated milk had positive effects on the end-product acid gels of low heat treatment and high heat treatment milk.

The purpose of this research was to find the effect of ratio of andaliman with garlic and aging time on the quality of sambal tuk tuk stored at room temperature. This research was using completely randomized design with two factors, i.e.: ratio of andaliman with garlic (A): (100%: 0%; 75%: 25%; 50%: 50%; 25%: 75%; 0%:100%) and aging time (L): (0, 4 and 8 day). Parameters analysed were moisture content, total number of microbe, vitamin C content, pH, total soluble solids, colour values (Chromatometer), hedonic organoleptic score of colour, flavour, taste and texture. The results showed that the ratio of andaliman with garlic has highly significant effect on moisture content, total number of microbe, colour score (Chromatometer), score hedonic of organoleptic colour, flavour, texture and texture score. The ratio of andaliman with garlic of (25%:75%) the best quality of sambal tuk tuk based from score of organoleptic and total number of microbe stored for up to 8 days at room temperature.

The panna cotta is one of the Italian desserts served cold. The row materials for this dessert are cream and milk that are cooked with other ingredients such as sugar and gelatine. The characteristics of panna cotta resemble pudding, but the gel nature of this dessert is softer and can melt in the mouth when eaten. This study was purposed to determine the quality characteristics of panna cotta after the use of konjac flour (Amorphophallus konjac) as the substitution of gelatine. This research was conducted using a non factorial completely randomized design with 4 replications, with konjac substitution to gelatine were 100%, 75%, 50%, 25%, and 0%. Based on the tests carried out, it was found that the substitution of konjac flour to gelatine had a very significant effect on texture, vitamin C levels, and syneresis. The resulting panna cotta of texture ranges from 0.2751 mm/g to 0.2870 mm / g. The resulting panna cotta of vitamin C levels ranges from 8.3745 mg/100g to 11.5922 mg/100g. The resulting panna cotta of syneresis ranges from 6.4199% to 4.2715%. In addition, the substitution had no significant effect on the colour (°Hue), pH value, and organoleptic (colour, flavour, taste, and texture).

The purpose of this research was to determine the effect of ratio of moringa leaves juice with pineapple juice and the best percentage of arabic gum on the quality of jelly candy. This research was using completely randomized design with two factors, i.e. : ratio of moringa leaves juice with pineapple juice (K): (100%:0% ; 75%:25% ; 50%:50% ; 25%:75% ; 0%:100%) and arabic gum percentage (G): (1,0% ; 1,5% ; 2,0%). Parameters analyzed were moisture content, ash content, vitamin C content, total soluble solid, total acid, lightness value (L*), hedonic organoleptic values of colour, flavour, taste, texture and score organoleptic values of colour and texture. The results showed that the ratio of of moringa leaves juice with pineapple juice had highly significant effect on ash content, vitamin C content, total acid, lightness value, hedonic organoleptic test of colour, flavour, taste and score organoleptic value of colour. The ratio of  moringa leaves juice with pineapple juice (25%:75%) and 2,0% arabic gum percentage produces the best quality of jelly candy based on hedonic organoleptic values of colour, flavour, taste, texture and score organoleptic values of colour and texture.

Orange-fleshed sweet potato (OFSP) is one type of sweet potatoes that is in great demand as it has attractive colour, high starch and fibre content, and excellent source of strong antioxidants, provide health beneficial effect. In this study, OFSP was processed into flour, starch, and residual flour from OFSP starch processing and they were used as ingredients for making biscuits to substitute the wheat flour. Ratios of wheat flour: OFSP flour: OFSP starch: residual flour were 85:5:5:5; 70:10:10:10; 55:15:15:15; and 40:20:20:20. The resulting biscuits were analysed for their textural property and sensory quality. The results showed the ratio of wheat flour, OFSP flour, starch and residual flour significantly affected the textural property and quality of sensory biscuits produced. Biscuits with the formula ratio of 55% wheat flour, and 15% OFSP flour, 15% OFSP starch and 15% OFSP residual flour had good textural properties and can also be accepted by consumers.

Gayo area is the largest Arabica coffee production in Asia. The materials used in this research were coffee beans which are natural, semi-washed, and fully-washed processed coffee. This study aimed to determine the physicochemical of green bean will the various processing. The moisture content of three green bean coffee were 9.78%, 9.60% and 11.03% for natural, semi-washed and full-washed processing, respectively. The ash content ranged from 3.19% for natural processing to 4.33% for full-washed processing. Full washed green bean coffee had the highest lipid content, 12.5 ± 0.20% compared to the other coffee. Moreover, the lowest pH and specific volume were found in natural processing coffee, 5.63 and 1.66 mL/g, respectively. The finding result shows that coffee characteristics depending on the processing methods. Future work will be done by applying various packaging for the coffee bean.