Dr. Floyd McKeith University of Illinois

Publish Date: June 6, 2006

The Food Marketing Institute (FMI, 2000) summarized the factors that consumers feel are important when making food purchasing decisions; ranked in descending order of importance were: (1) taste; (2a) nutrition, (2b) food safety, (4) cost and (5) storability. At the same time, consumers still try to economize when shopping: (a) low prices ranked 8th in Importance of Supermarket Features, and (b) 20% or more of supermarket shoppers did one or more of the following economizing behavior--looked in newspaper for grocery specials, participated in frequent shopper programs, stocked-up on bargain items, used cents-off coupons, compared prices at different supermarkets (FMI, 2000). These factors indicated that consumers are still very conscious of value (satisfaction received for price paid).

Publish Date: June 3, 2006

Increasing muscle pH and improving fresh pork quality are objectives of the pork industry. Factors at all stages of production can contribute to fresh pork quality and sensory characteristics. Pre-slaughter handling is an area that has been targeted to improve pork quality. The effects of feed withdrawal prior to slaughter have been evaluated utilizing a wide range of approaches. Early research focused on economically important losses that occurred when pigs were marketed on a live weight basis and animals were off feed during extended transport or lairage. Feed withdrawal before slaughter has been evaluated recently because it can potentially improve pork quality by increasing ultimate pH, increasing water holding capacity, improving color and reducing the incidence of PSE pork. However, there are potential deleterious effects of feed withdrawal on live weight, carcass weight, liver characteristics, and stomach ulcers.

Publish Date: June 3, 2006

Ractopamine hydrochloride (RAC or PayleanTM) is a phenethanolamine with beta-adrenergic agonist properties. The FDA approved the use of Ractopamine, up to 18g/T for finishing swine weighing up to 240 pounds (109 kilograms). The recommended usage today is at a level of 4.5 to 9g/T for the last four weeks of the finishing period. The effects of RAC on carcass composition and pork quality have been characterized in the literature. The majority of the research in the literature was conducted prior to 1990. There have been numerous production changes in the last decade. Those changes include genetics and management practices. The emphasis on quality and the techniques used to evaluate quality have also changed drastically during this time period. The importance of pork quality is major issue to the industry. Pork quality is not clearly defined and may describe a wide range of characteristics. For the purpose of this review, it will be defined as the visual characteristics (color, water-holding capacity and marbling) and eating quality (tenderness, juiciness and flavor). The objective of this paper is to provide a broad overview of pork quality measurements, examine past research addressing the impact of PayleanTM on fresh pork quality and the current status of knowledge relating to the impact of PayleanTM on pork quality.

Publish Date: June 3, 2006

This paper reviews the literature relating to the potential impact of swine nutrition on pork quality attributes. Supra-nutritional levels of vitamin E have been shown to increase muscle vitamin E content and reduce lipid oxidation; however, the impact on muscle color and water holding capacity has been variable. Selenium is also potentially involved in reducing lipid oxidation; there is no evidence, however, that supplying additional selenium above the requirement improves pork quality. Recent research has suggested that the feeding of high levels of vitamin D3 in the final 10 days prior to slaughter improves pork color and reduces drip loss; these results require validation. Feeding ingredients with relatively high levels of unsaturated fatty acids increases the degree of unsaturation of the fat tissue, decrease fat firmness, and can negatively impact fat quality. The potential to produce “healthier” pork by feeding ingredients rich in omega-3 fatty acids and to improve fat firmness by including conjugated linoleic acid in the diet is discussed. There is evidence that restricted feeding of growing-finishing pigs can negatively impact pork tenderness and juiciness. The marbling fat content of pork has been positively associated with eating quality and feeding protein-deficient diets in the final 5 weeks prior to slaughter has been shown to increase marbling. Australian research has suggested that supplementation of diets with magnesium aspartate for 5 days prior to slaughter reduces the incidence of PSE and improves muscle color and water holding capacity. A range of other dietary compounds has been investigated; however, there is limited evidence on which to judge their efficacy for improving pork quality under commercial conditions.