Development of formulation of pudding containing caseinomacropeptide

Caseinomacropeptide is a polypeptide released to whey by the activity of rennet enzyme during cheese manufacturing. Fragmentation occurs at Phe105-Met106 peptide bond. Caseinomacropeptide is isolated from whey by ultrafiltration and chromatography techniques. Caseinomacropeptide is a peptide with structural and nutritional functional properties. Absence of phenylalanine in amino acid sequence makes it valuable as a protein source for diet of phenylketonuria patients. Caseinomacropeptide being rich in branched-chain aminoacids and poor in methionine is a suitable component in diet of hepatic patients. Caseinomacropeptide has functional properties improving health such as binding bacteria enterotoxins, supporting immune system and growth o probiotics and inhibiting secretion of gastric juices. Structural functional properties of caseinomacropeptide include gel, foam and emulsion formation. Caseinomacropeptide is a water-soluble hydrophilic molecule and is negatively charged even at low pH. Caseinomacropeptide has been used for preparation of different food products for diet of phenylketonuria patients. Pudding can also be prepared by using caseinomacropeptide for replacement of milk proteins. In pudding, milk proteins play an important role in structure formation with starch. Caseins in the milk are trapped between the amylose network and strengthen the network structure in pudding. Corn starch gives the typical texture and structure to the puddings. Stabilizers reduce serum separation by binding free water and protect the gel after processing such as pumping, mixing and cooling. The stabilizers extend the shelf life of the product and provides acceptable homogeneity between product parties. Stabilizers commonly used in pudding are -carrageenan, locust bean gum and gellan gum. In this study, a formulation was developed for production of a pudding including caseinomacropeptide isolate as protein source instead of milk. Nonfat milk powder, corn starch, sugar and water were used in a basic formula to prepare control sample. Caseinomacropeptide containing sample was prepared by using caseinomacropeptide isolate in place of 10% nonfat milk powder by the same formula and production method. Pudding samples were prepared by mixing with a magnetic stirrer in a water bath. Heating was carried out at 40°C for one hour to ensure dissolution of nonfat milk powder and caseinomacropeptide in water. Then corn starch, sugar and gums were added and the temperature was raised to 90°C and heated for 10 minutes with stirring. Aluminium foil was used as a cover to prevent loss of water from the surface during heating. After heating, the samples were taken into a cold water bath and brought to room temperature and kept at 4°C until analyses were made. Since the sample with caseinomacropeptide had watery and weak structure with excessive water separation, preliminary trials were carried out to improve its physical properties. In preliminary trials, increasing amount of starch and used of different gums were investigated. Use of increasing amount of starch hardened the structure but led to water separation. When Na-alginate, carboxymethyl cellulose and κ-karagenan were used as single gum, excessive water separation from the structure was observed. When locust bean gum was used, structure was hardened and water separation was reduced depending on the amount used. Based on the results from preliminary trials, samples of puding with caseinomacropeptide were prepared without any gum and with 0,02-0,2% κ-carrageenan, 0,5-0,7% locust bean gum, 0,5% locust bean gum-0,02%κ-carrageenan ve 0,5% locust bean gum-0,2%κ-carrageenan and compared with the sample with nonfat milk powder in terms of physical properties. Pudding samples were analysed after 1 hour from the preparation. Water separation was measured by using 20 g of sample. The sample was centrifuged at 4000 rpm and 4°C. After centrifugation, the separated serum was removed and weighed to determine the amount of serum removed. In rheological analyses, stress and frequency sweeps were carried out at 10C to determine strength and stability of pudding samples. Parallel plate sensor system was used in measurements. Stress sweep was done between 0-1000 Pa at 0.1 Hz frequency. Maximum elastic modulus (G') value was taken as gel hardness. Shear stress at crossover point of G' and viscous modulus (G'') was taken as yield stress. Frequency sweep was done between 0,1-100 Hz at a shear stress value in linear viscoelastic region. Samples were prepared separately for texture analyses. A cylindrical probe with a diameter of 10 mm was used for measurements at 4C. Puncture test where the probe was inserted to the sample to a depth of 5 mm and then extracted from the sample. Maximum force was taken as hardness, the work for entry as penetration work, the force applied for exit as adhesive force and the work done for exit as adhesiveness. Sensory analyses were done on selected samples including the samples control, 0.5% locust bean gum-0.02%κ-carrageenan ve %0.7 locust bean gum. Descriptive sensory analysis method and scale of 0-5 were used for analysis. The samples were compared for consistency, lightness, particulated structure, particle size and whiteness. Water separation was highest in the samples without gum and with only κ-carrageenan. These samples were followed by the samples with locust bean gum and κ-carrageenan combination. The samples with only locust bean gum had lower water separation than those of other samples. The sample with 0.7% locust bean gum had no water separation as the sample with nonfat milk powder. In rheological analyses in the samples, 0.1 Hz frequency, 0-1000 Pa stress scanning was done.The sample with nonfat milk powder was found to have the highest gel hardness and yield stress. The caseinomacropeptide sample was found to have the weakest gel structure. The samples with 0.2% κ-carrageenan and 0.7% locust bean gum were found to be closest to the sample with nonfat milk powder in terms of gel properties. Firmness and adhesiveness were highest in the sample with nonfat milk powder, lowest in the sample with only caseinomacropeptide. The textural properties of caseinomacropeptide samples with 0.5% locust bean gum-0.2%κ-carrageenan and 0.7% locust bean gum were found to be closest to those of the sample with nonfat milk powder. The samples with lower water separation and higher hardness compared to those of the other samples including 0.5% locust bean gum-0.02%κ-carrageenan ve %0.7 locust bean gum were chosen for sensory analysis. The samples with caseinomacropeptide had lower consistency, particulated structure and particle size but higher lightness and whiteness scores compared with those of the sample with nonfat milk powder. The sample with 0.7% locust bean gum had higher consistency and lower particulated structure score when compared with the sample containing %0,5 locust bean gum-%0,02 κ-carrageenan. Addition of locust bean gum to the pudding containing caseinomacropeptide instead of nonfatmilk powder was found to stregthen the structure and prevent water separation. Level of locust bean gum was found to be important to obtain hardness similar to that of the milk containing pudding and no water separation. Use of locust bean gum was recommended for formulation of pudding with caseinomacropeptide for obtaining desired structural and sensory properties.