Determination of Soy Products in Meat-Soy Blends

Abstract

The concentrations of various elements and fiber in ground beef and textured soy flour were measured, respectively, by atomic absorption spectrophotometry and a modified AOAC fiber method. The average concentration, standard deviation, and coefficient of variation for magnesium, manganese, and fiber, respectively, in textured soy flour are 2948 mg/kg, 186 mg/kg, 6.3% ; 33.4 mg/kg, 3.4 mg/kg, 10.1% ; 2.03%, 0.27%, 13.3%. The average concentration, standard deviation, and coefficient of variation for magnesium, manganese, and fiber, respectively, in regular ground beef are 151 mg/kg, 7.4 mg/kg, 4.9% ; 0.125 mg/kg, 0.025 mg/kg, 20%; 0.01%. From computer analysis of the data from an interlaboratory study of the analysis of textured soy flour–ground beef mixtures, the expected total errors (one standard deviation in absolute percentages) of the method applied to a product containing 20% textured soy flour hvdrated 1+2 were as follows for the respective indices used: magnesium 1.8%, manganese 2.7%, and fiber 8.8%. Analysis of ground beef and textured soy flour for ash, hemicellulose, stachyose, phosphorus, potassium, copper, and zinc revealed that these constituents were not suitable indices of textured soy flour content in textured soy flour-ground beef mixtures.

Determination of soya protein in processed foods

“…Many studies have been attempted to solve the problem of determining the amount of vegetable protein added to processed foods. Quantitative procedures that have been investigated but do not really solve the problems are 13C:1zC isotopic ratios (35), metal and fiber analysis (36), determination of phytate (37) and analysis for conavanine (38).…”

Detection of soybean in soy‐based meat substitutes

“…crude fiber method yields erratic results with ground beef because some protein which is difficult to digest with I .25"; H,SO, or 1.25"0 NaOH is measured as fiber. A modified procedure was devised to include a predigestion with alcoholic KOH before the standard crude fiber analysis [27].…”