Production of protein hydrolysate from shrimp precooking water using enzyme Nutrase 0.5 L was studied. Variations in the enzymatic hydrolysis were composed of the quantity of enzyme (0, 0.5, 1.0, 1.5 and 2.0 percent v/v), the pH (5.5, 6.5 and 7.5), the hydrolysing temperature (50, 55 and 60 deg C) and the hydrolysing time (15, 30, 45, 60, 75 and 90 min). The optimum condition for production of hydrolysate which gave the maximum amino acid nitrogen at 3.50 mgN/ml was 0.5 percent Nutrase, pH 6.5 50 deg C and 10 min. The chemical composition of the hydrolysate produced was 94.51 percent moisture, 2.52 percent protein, 0.33 percent fat, 1.77 percent ash and 0.88 percent carbohydrate. The hydrolysate was then freeze-dried. The dried product absorbed moisture quite easily and contained 3.80 percent moisture, 51.89 percent protein, 6.57 percent fat, 24.76 percent ash and 12.99 percent carbohydrate. To improve the quality of the dried product, the hydrolysate was mixed with 20 percent maltodextrin solution until the mixture had 10 percent total soluble solid before freeze-drying. It was found that the dried product absorbed moisture less rapidly and was ground easily. The composition of the improved product was 5.23 percent moisture, 36.98 percent protein, 3.71 percent fat, 16.61 percent ash and 41.98 percent carbohydrate. Sensory evaluation on the color and shrimp odor of these two dries products comparing to the freezed-dried unhydrolysed precooking water products showed that the freezed-dried hydrolysate without maltodextrin solution obtained the highest scores in color and odor. However, sensory evaluation the products after dissolving in water revealed that neither the hydrolysed nor unhydrolysed products had the significant differences in color, shrimp for, sweet taste, bitter taste and overall flavor.

Food reformulation, either to reduce nutrient content or to enhance satiety, can negatively impact upon sensory characteristics and hedonic appeal, whilst altering satiety expectations. Within numerous food systems, perception of certain sensory attributes, known as satiety-relevant sensory cues, have been shown to play a role in food intake behaviour. Emulsions are a common food structure; their very nature encourages reformulation through structural design approaches. Manipulation of emulsion design has been shown to change perceptions of certain sensory attributes and hedonic appeal, but the role of emulsions in food intake behaviour is less clear. With previous research yet to identify emulsion designs which promote attributes that act as satiety-relevant sensory cues within emulsion based foods, this paper investigates the effect of oil droplet size (d4,3: 0.2–50μm) and flavour type (Vanilla, Cream and No flavour) on sensory perception, hedonics and expected food intake behaviour. By identifying these attributes, this approach will allow the use of emulsion design approaches to promote the sensory characteristics that act as satiety-relevant sensory cues and/or are related to hedonic appeal. Male participants (n=24) assessed the emulsions. Oil droplet size resulted in significant differences (P<0.05) in ratings of Vanilla and Cream flavour intensity, Thickness, Smoothness, Creamy Mouthfeel, Creaminess, Liking, Expected Filling and Expected Hunger in 1h’s time. Flavour type resulted in significant differences (P<0.05) in ratings of Vanilla and Cream flavour intensity, Sweetness and Liking. The most substantial finding was that by decreasing oil droplet size, Creaminess perception significantly increased. This significantly increases hedonic appeal, in addition to increasing ratings of Expected Filling and decreased Expected Hunger in 1h’s time, independently of energy content. If this finding is related to actual eating behaviour, a key target attribute will have been identified which can be manipulated through an emulsions droplet size, allowing the design of hedonically appropriate satiating foods.