Peanut quality ‘thermal analysis’ tool for roasters

Swiss global manufacturer and marketer of precision instruments Mettler Toledo has launched new equipment in Australia designed to help manufacturers ‘optimise’ the roasting process for peanuts.

Mettler Toledo said the equipment, known as Differential Scanning Calorimetry (DSC 1), allows manufacturers to avoid under- or over-roasting peanuts, which can “significantly affect the colour, flavour, texture and shelf-life of the end product”.

The Company said DSC 1 provides manufacturers with “valuable information on the temperature and time conditions required for optimum texture, flavour and colour, as well as determining the effect oil-roasating has on the undenatured nonarachin and arachin proteins of the peanut”.

Analysing the roasting process of peanuts

Mettler Toledo said testing peanuts with the DSC 1 equipment involves grating the nuts into a fine powder and putting them into “medium pressure crucibles”. An equal amount in weight of water is added before the crucibles are sealed.

Testing undertaken by Mettler Toledo established the optimum temperature and time conditions by determining the effect oil-roasting had on the peanuts’ levels of residual undernatured arachin and nonarachin protein fractions. According to the Company, evaluation indicated that temperatures in the range of 149-163 degrees Celsius for 5 to 8 minutes were required for optimum finished product texture, flavour and colour.

Data collected by Mettler Toledo indicated that blanched peanuts exhibited a small starch gelatinisation endotherm at 80 degrees Celsius, which indicated that some gelatinisation had already occurred during blanching. However, according to the Company, the denaturation peaks for nonarachin 98 degrees Celsius and arachin at 113 degrees Celsius, which suggested that blanching had not resulted in “any significant protein denaturation”.

By comparison, Mettler Toledo said roasting resulted in a smaller residual starch gelatinisation peak, the absence of the nonarachin peak and a broadened arachin peak, which is significantly reduced in size. The Company said this suggested that arachin is partially denatured, due to over-roasting a too high a temperature.

DSC 1 helps optimise raw material selection and roasting process

Mettler Toledo said the DSC 1 equipment provides manufacturers with a “fast and easy technique” to establish criteria for selecting raw material and for optimising the roasting process of peanuts.

“The DSC 1 is an extremely useful instrument for quality control, research and development and, ultimately, for satisfying consumer expectations,” said the Company.

Source: Mettler Toledo