Towards on-line prediction of dry matter content in whole unpeeled potatoes using near-infrared spectroscopy.

Prediction of dry matter content in whole potatoes is a desired capability in the processing industry. Accurate prediction of dry matter content may greatly reduce waste quantities and improve utilization of the raw material through sorting, hence also reducing the processing cost. The following study demonstrates the use of a low resolution, high speed NIR interactance instrument combined with partial least square regression for prediction of dry matter content in whole unpeeled potatoes. Three different measuring configurations were investigated: (1) off-line measurements with contact between the potato and the light collection tube; (2) off-line measurements without contact between the potato and the light collection tube; and (3) on-line measurements of the potatoes. The offline contact measurements gave a prediction performance of R(2)=0.89 and RMSECV=1.19. Similar prediction performance were obtained from the off-line non-contact measurements (R(2)=0.89, RMSECV=1.23). Significantly better (p=0.038) prediction performance (R(2)=0.92, RMSECV=1.06) was obtained with the on-line measuring configuration, thus showing the possibilities of using the instrument for on-line measurements. In addition it was shown that the dry matter distribution across the individual tuber could be predicted by the model obtained.

Effect of dietary selenium and omega-3 fatty acids on muscle composition and quality in broilers.

BACKGROUND: Human health may be improved if dietary intakes of selenium and omega-3 fatty acids are increased. Consumption of broiler meat is increasing, and the meat content of selenium and omega-3 fatty acids are affected by the composition of broiler feed. A two-way analyses of variance was used to study the effect of feed containing omega-3 rich plant oils and selenium enriched yeast on broiler meat composition, antioxidation- and sensory parameters. Four different wheat-based dietary treatments supplemented with 5% rapeseed oil or 4% rapeseed oil plus 1% linseed oil, and either 0.50 mg selenium or 0.84 mg selenium (organic form) per kg diet was fed to newly hatched broilers for 22 days. RESULTS: The different dietary treatments gave distinct different concentrations of selenium and fatty acids in thigh muscle; one percent linseed oil in the diet increased the concentration of the omega-3 fatty acids 18:3, 20:5 and 22:5, and 0.84 mg selenium per kg diet gave muscle selenium concentration at the same level as is in fish muscle (0.39 mg/kg muscle). The high selenium intake also resulted in increased concentration of the long-chain omega-3 fatty acids EPA (20:5), DPA (22:5) and DHA (22:6), thus it may be speculated if high dietary selenium might have a role in increasing the concentration of EPA, DPA and DHA in tissues after intake of plant oils contning omega-3 fatty acids. CONCLUSION: Moderate modifications of broiler feed may give a healthier broiler meat, having increased content of selenium and omega-3 fatty acids. High intakes of selenium (organic form) may increase the concentration of very long-chain omega-3 fatty acids in muscle.