Comparison of milks processed by the direct and indirect methods of ultra-high-temperature sterilization. IV. The vitamin composition of milks sterilized by different processes

Abstract

SummaryA comparison was made of the effects of direct and of indirect ultra-high-temperature (UHT) processing of milk, under standardized operating conditions giving equal sporicidal effects, on some of the more labile water-soluble vitamins and on vitamin A and carotene. The effects of processing per se were negligibly small, and the method of processing was important only in so far as the presence of residual oxygen in the sterilized milk has been found to cause losses of folic acid and ascorbic acid during storage subsequent to sterilization. The incorporation of a de-aerator vessel, to reduce the oxygen level in the indirectly heated milk and so eliminate the adverse effects of oxygen during storage, had no effect on the vitamin loss occurring during heat treatment. It is concluded that milk produced by indirect heating plant incorporating a de-aerator should be similar in vitamin content to milk produced on a direct heating plant, both immediately after processing and after storage.

A Systematic Review and Meta-Analysis of the Effects of Pasteurization on Milk Vitamins, and Evidence for Raw Milk Consumption and Other Health-Related Outcomes

“…Fleterogeneity also was significant (P < 0.001; T2 = 4.85); five studies contributed to this heterogeneity (30,35,40,41,52). (2,9,10,61), and one was observational (43). T he effect size obtained w ith the random effects m odel was -11.99 (95% C l, -20.95, -3.03) (Fig.…”

“…Panfili et al (62) reported a numeric increase in vitamin A concentrations across a range of pasteurization conditions, all of which were significant in seven of eight studies. Vitamin B12 levels were numerically reduced after pasteuri zation at a range of temperatures (9, 10,13,26,28,60,61).…”

“…Six o f the 18 trials contributed to the heterogeneity (46,73,(77)(78)(79). In total, 19 studies w ere conducted on the effects o f pasteurization on vitam in C. O f these, nine did not include a m easure o f data dispersion (10,26,29,33,39,51,61,83,97), tw o articles included the results in text (2,7), and one study was observational (65); therefore, only seven studies were included in the m eta-analysis. In the m ajority o f trials, a num eric decrease in vitam in C w as found after heat treatm ent.…”

Effect of Initial Dissolved Oxygen Levels on the Degradation of Ascorbic Acid and the Browning of Lemon Juice during Storage

“…Eliminating oxygen completely by storage in glass containers with zero headspace considerably reduced the rate of ascorbic acid degradation, 70% still being present after 10 wk at 24°C. Burton et al (1970) found that the stability of ascorbic acid was wholly determined by the level of residual oxygen in sterilized milk and not by the method of processing. When the oxygen content was low, ascorbic acid was stable indefinitely.…”

Ácido fólico em leite e bebida láctea enriquecidos: estudo da vida-de-prateleira

“…Para a limpeza do extrato transferiu-se quantitativamente a solução para balão volumétrico de 10mL, adicionou-se 3,0mL de ácido fosfórico (0,1mol/L, MERCK, Brasil), 2,0mL de tampão fosfato, composto por Na 2 Considerando que os produtores tenham realmente adicionado ácido fólico numa quantidade de pelo menos 100% a mais, o que é recomendado pelos fabricantes de "premix", as variações das diferenças entre os valores encontrados e dos apresentados nos rótu-los, podem, ser explicadas pelas condições de processamento, concentração de oxigênio dissolvido durante e após o processo. Fatores como esses foram relatados anteriormente por BURTON et al [4] e DONG & OACE [10]. De acordo com esses autores, quanto maior a quantidade de oxigênio incorporado ao alimento e maior a A. M ± DP-média e estimativa do desvio padrão das determinações em duplicata CV-coeficiente de variação * Amostra analisada 4 meses após fabricação.…”