Evaluacion de la eficacia del ultrasonido y campos magneticos como metodos de conservacion de la carne fresca de cerdo de la raza pietrain y su impacto sobre las propiedades fisicas, quimicas y microbiologicas

Abstract

In this project was studied the effect of the treatment with Ultrasound of high frequency (US) and magnetic fields (CM) on the conservation and some properties of the pork of the race Pietrain, For this purpose, there were realized courts of meat of the leg of the pig and surrendered to ultrasound (37 kHz) and magnetic Fields CM (0,1147T/16°C) during 5, 10, 15 and 20 minutes respectively and later evaluated the effect on the protein, fat, moisture, Capacity of water retention (CRA), pH, Capacity Emulsifier (CE), Acidity, Color, profile Analysis of Texture (TPA), and inventory of aerobic mesophylls after maintaining in refrigeration to 4°C on the 3,6,9,12,15rd after applied the treatments. The results of the characterization of pork of the race Pietrain showed that the parameters of pH, moisture, fat and protein are equal to the brought ones by the literature. The CE 5,19 ml/10g, the CRA is 18 %, the microbial load of aerobic mesophylls is 75*10ufc/g. In the samples treated with Ultrasound, were observed differences statistically significant (p <0,05) on the decrease of the pH and the fat in all the treatment times. In addition presented an increase in the content of protein and the CE during all the treatment times, while the moisture and the CRA diminished; on the other hand the acidity increased during the first 10 minutes and during the 15, and 20 minutes a statistically significant decrease was observed (p <0,05) regarding to the sample control. For all the treatments applied with US and CM min observed an increase regarding to the luminosity L* during 5, 10, 15 and 20. The texture profile study shows that during the treatment with US and CM min that the characteristics of chewiness, hardness and cohesiveness present a significant increase (p <0,05), while the elasticity decreased. On the other hand during the time of 10 min the chewiness and the elasticity present the biggest significant increase, while the cohesiveness maintains a minimally significant tendency to increase after the treatments. The hardness diminished proportionally to the treatment time with US and CM. The chewiness and the elasticity tend to increase after the 15 min. The treatment during 5 minutes with US and CM did not show effect in the decrease of the presence of aerobic mesophylls, while times superior to 10 minutes, a decrease was demonstrated as per statistics significant (p <0,05), even up to 9 days of storage