Effects of Sources or Formulations of Vitamin K(3) on Its Stability during Extrusion or Pelleting in Swine Feed

SIMPLE SUMMARY: Pelleting or extrusion have been used in the feed industry to improve nutrient utilization and reduce the load of pathogenic microorganisms. High temperature and high pressure during this process cause loss of heat-sensitive vitamins, such as vitamin K(3) (VK(3)). Encapsulation techniques have been gradually applied to feed additives, which may improve the stability of vitamins. Our previous work has shown that VK(3) was the most unstable vitamin during heat processing. Therefore, the aims of this study were to determine the effects of sources, formulations of VK(3), extrusion temperature and pelleting parameters on its stability. The results indicate that menadione nicotinamide bisulfite (MNB) is more stable than menadione sodium bisulfite (MSB) during high temperature and high-pressure processing. The micro-capsule/micro-sphere formulation VK(3), manufactured through the encapsulation technique, had a higher recovery during pelleting but not during extrusion. Therefore, a reasonable decrease in the intensity of feed processing and choosing a more suitable formulation of VK(3) could be a solution for accurate VK(3) nutrition, according to current research results. ABSTRACT: Two studies were conducted to determine the stability of vitamin K(3) (VK(3)) in swine diets during extrusion or pelleting. The two sources were menadione sodium bisulfite (MSB) and menadione nicotinamide bisulfite (MNB), and the three formulations were crystal micro-capsule formulation and micro-sphere formulation. The recovery of six types of VK(3) in swine diets was investigated after extrusion at 100 °C or 135 °C in Experiment 1. The recovery of six types of VK(3) was investigated when the diets were pelleted at 60 °C (low temperature; LT) or 80 °C (high temperature; HT) and the length to diameter ratios were 5.2:1 (low length to diameter ratio; LR) or 7.2:1 (high length to diameter ratio; HR) in Experiment 2. In Experiment 1, MNB recovery (72.74%) was higher than MSB recovery (64.67%) after extrusion, while recovery of VK(3) of crystal (74.16%) was higher than the recovery of micro-capsule (65.25%) and micro-sphere (66.72%). The recovery of VK(3) (70.88%) was higher when extruded at 100 °C than that at 135 °C (66.54%). In Experiment 2, MNB recovery (86.21%) was higher than MSB recovery (75.49%) after pelleting, while the recovery of VK(3) of micro-capsule (85.06%) was higher than the recovery of crystal (81.40%) and micro-sphere (76.09%). The recovery of VK(3) (75.50%) was lower after HTHR pelleting than LTLR (83.62%), LTHR (81.52%) or HTLR (82.76%) treatment. Our results show that MNB has greater stability than MSB. VK(3) of crystal or VK(3) of micro-capsule were recommended for extrusion or pelleting, respectively.