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PROTEIN DISPERSIBILITY INDEX AND PROTEIN SOLUBILITY IN POTASSIUM HYDROXID AS INDICATORS OF THE DEGREE OF FULLFAT SOYBEAN HEAT TREATMENT
Dragan Palić
; Institute for Food Technology, Novi Sad, Serbia
Kedibone Yvonne Modika
; Institute for Animal Production, Agricultural Research, Council, Private Bag X2, Irene 0062, South Africa
Sophia Elisabeth Coetzee
; Institute for Animal Production, Agricultural Research, Council, Private Bag X2, Irene 0062, South Africa
Jovanka Lević
; Institute for Food Technology, Novi Sad, Serbia
Bojana Kokić
; Institute for Food Technology, Novi Sad, Serbia
Nedeljka Peno
; Institute for Food Technology, Novi Sad, Serbia
Sažetak
Soybean prior to oil extraction is referred to as full-fat soybean (FFSB). Raw FFSB contains anti-nutritional factors (ANFs), which can be destroyed by moderate heating. Both over- and under- heat processing will limit the level of amino acids available to the animal. There is a number of laboratory methods that can be used to estimate the degree of FFSB heat treatment. Two of them, Protein dispersibility index (PDI) and Protein solubility in potassium hydroxide (PSKOH), are based on protein solubility, which was claimed to be the most reliable indicator of the degree of FFSB heat treatment. This paper presents the results of an inter-laboratory study conducted to determine the repeatability limits of the PDI and PSKOH methods. Five samples of FFSB were processed by dry extrusion at temperatures between 110 °C and 164 °C and sent to 8 laboratories for PDI determination and to 9 laboratories for PSKOH analysis. The repeatability limit for the PDI method was found to be 2.31 index units, whereas for the PSKOH method the obtained repeatability limit was 3.77%. Both methods generated acceptable repeatability limits. Due to relatively expansive special blender required for the PDI analysis, which is not always available to laboratories, the preference in routine, every-day analysis should be given to the PSKOH method.
Ključne riječi
full-fat soybean; heat treatment; protein dispersibility index; protein solubility in potassium hydroxide; repeatability limit
Hrčak ID:
60602
URI
Datum izdavanja:
15.8.2010.
Posjeta: 2.657 *