Temperature could impact pasta quality.

Scientists at Michigan State University have investigated the effects of drying temperatures on various starch properties and the quality of pasta. In their research, a short-cut pasta (fusilli) was processed from durum semolina. The product was dried using high temperature (HT) and very high temperature (VHT) cycles. The investigators found that changes in starch during the HT and VHT drying processes may affect the pasta's cooking quality.

The researchers examined starch properties using differential scanning calorimetry, X-ray diffractometry, polarized light microscopy and other instrumental techniques. The cooking quality was evaluated by determining the cooking loss (CL) in cooking water and the total organic matter (TOM) in the washing water after cooking. Sensory evaluation also was undertaken.

The X-ray diffractograms of semolina samples showed typical A-type diffraction patterns. The diffractograms of pasta products processed using the HT and VHT drying techniques were similar. However, an additional small peak appeared on the diffractograms for both drying cycles, indicating the formation of a V-type X-ray diffraction pattern. All starch granules of semolina had a "Maltese cross" image under polarized light. Approximately 20% of starch granules of HT- and VHT-dried pasta samples either partially or completely lost their birefringence.

Starch from VHT-dried pasta had greater peak viscosity and breakdown viscosity than HT-dried pasta. Both the gelatinization enthalpy and the peak temperature of HT-dried pasta were significantly lower than those of VHT-dried pasta. The HT-dried pasta had lower quality scores based on TOM values, CL values and sensory evaluation, as compared with the VHT-dried pasta.

Further information. Perry Ng, Department of Food Science and Human Nutrition, Michigan State University, 135 Food Science Building, E. Lansing, MI 48824-1224; phone: [phone]; URL: www.msu.edu.