A comprehensive review of Nε-carboxymethyllysine and Nε-carboxyethyllysine in thermal processed meat products

Air frying combined with grape seed extract inhibits Nε-carboxymethyllysine and Nε-carboxyethyllysine by controlling oxidation and glycosylation

Advanced glycation end products (AGE), compounds formed in meat at the advanced stage of Maillard reaction, are easily exposed to thermal processing. Improving cooking condition and adding antioxidants are 2 common ways for AGE reduction. The present work compared the inhibition of grape seed extract (GSE) on levels of free and protein-bound N^ε-carboxymethyllysine (CML) and N^ε-carboxyethyllysine (CEL) in chicken breast under deep-frying and air-frying conditions. Efficiency of 5 concentrations of GSE (0.0, 0.2, 0.5, 0.8, and 1.0 g/kg) in retarding oxidation, glyoxal (GO), methylglyoxal (MGO), lysine (Lys), Maillard reaction degree (A₂₉₄, A₄₂₀), and Shiff's base were tested. Results showed that 0.5 g/kg GSE before heating significantly (P < 0.05) reduced AGE in fried breast chicken, whereas excessive supplementation of GSE (0.8 and 1 g/kg) was reverse. Air frying was found significantly (P < 0.05) better than deep frying to reduce the precursor substances (GO, MGO, and Lys) of AGE. In conclusion, GSE-derived polyphenols exhibited different inhibitory effects on oxidation and glycosylation at different concentrations. We found that 0.5 g/kg of GSE combined with air frying was the best recommendation for inhibiting CML and CEL.

Monitoring Thermal Treatments Applied to Meat Using Traditional Methods and Spectroscopic Techniques: a Review of Advances over the Last Decade

Thermal treatments are often applied during processing or preparation of muscle foods aiming to both improve the palatability and organoleptic properties and to ensure the safety of the treated food. However, the application of inappropriate or severe thermal treatments can lead to undesirable changes in the sensory and nutritional quality of heat-processed products, and especially so for foods that are sensitive to thermal treatments, such as meat and meat products. The impact of traditional and new heat processing technologies (e.g. microwaving, ohmic, and radio frequency heating) on meat quality has been widely assessed by a wide range of conventional methods, such as sensory, microbiological, and physicochemical methods. Due to the destructive nature and the time required to perform these assessments, alternative online methods are highly needed in order to achieve continuous monitoring through online applications. In this review paper, both traditional and new heat processing methods and their impact on the quality of meat will be first briefly presented. The methods and techniques that have been applied to monitor changes induced by application of thermal treatments will be then discussed. The main focus will be put on the application of spectroscopic techniques, as rapid and non-destructive methods compared to most conventional techniques. Finally, future trends and possible applications and research directions will be suggested.

Formation of protein-bound Nε-carboxymethyllysine and Nε-carboxyethyllysine in ground pork during commercial sterilization as affected by the type and concentration of sugars

This research was aimed to investigate the formation of protein-bound N^ε-carboxymethyllysine (CML) and N^ε-carboxyethyllysine (CEL) in ground pork at 121 °C (5-30 min) as affected by sugars (1-9% w/w, glucose, fructose, lactose, and sucrose).The addition of reducing sugar significantly (P < 0.05) increased the levels of CML and CEL in heat treated pork samples. Even adding 1% of glucose in pork could lead to 3.8 and 4.0 times increase in the formation rate constant (zero-order) of CML and CEL, respectively. In a typical commercial sterilization process (121 °C, 30 min), adding glucose, fructose or lactose in pork resulted in an average increase of 224-581%, 26-276%, and 8-189% CML, and 217-720%, 213%-15.8 times, and 20-150% CEL, respectively, depending on the sugar concentration. Sucrose did not promote the formation of CML and CEL in pork during heating.