Effect of Several Heat Treatments and Frozen Storage on Thiamine, Riboflavin, and Ascorbic Acid Content of Milk

Abstract

This research was designed to test the reliability of modified Association of Official Analytical Chemists methods for quantitation of thiamine, riboflavin, and ascorbic acid in milk; to ascertain the extent of destruction of those vitamins by modern heat processing; and to determine if it is truthful to report that heat processing does not reduce milk's nutritional properties insofar as those vitamins are concerned. Milk was processed continuously at four time-temperature treatments, including that used for modern commercial sterilization. Both raw and heated milks were analyzed immediately for content of heat labile vitamins; subsamples were packaged in amber plastic bottles, frozen, and subsequently analyzed for vitamin content after 14 days storage. Analyses were by modified Association of Official Analytical Chemists fluorometric techniques.

Thermal degradation kinetics of ascorbic acid, thiamine and riboflavin in rosehip (Rosa canina L) nectar

“…There are several studies about the thermostability of riboflavin on different foods and model systems. (Kwok et al, 1998;Ang et al, 1975;Haddad & Loewenstein 1983;Lavigne et al, 1989). However, while studies on the thermal stability of thiamine and riboflavin in fruit nectars are very limited, there is no in the rosehip nectar.…”

The FAST index – A highly sensitive indicator of the heat impact on infant formula model

“…In our experimental conditions strong losses of vitamin C were observed in a very short time, e.g., 23.3% after 9.5 min at 80°C and 56% after 3.5 min at 110°C. Haddad and Loewenstein (1983) also observed a rapid degradation of vitamin C in milk, 21.3% and 25.6% loss after heating at 80°C for 16 s and at 110°C for 3.5 s, respectively, despite the absence of iron fortification.…”

A highly sensitive and stable glucose biosensor using thymine-based polycations into laponite hydrogel films

“…This detection limit is comparable to the maximum concentration of AA found in fresh milk, e.g. 0.11 mmol L -1 [50]. Therefore, in a 1/1000 sample dilution, as typically used in electroanalysis of milk, the final AA concentration into the electrochemical cell should not interfere in the glucose quantification of milk samples.…”

“…Electroanalysis of glucose in real samples can involve the evaluation of both ascorbic (AA) and/or uric acids (UA) as potential interferents [50,51]. Hence, the contribution of AA and UA to the analytical current with the present bioelectrode was evaluated.…”