To analyze the yogurt amino acid profile starting from marketing through the whole shelf-life. The evaluation of the proteolytic activity of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus, allows to deduce their vitality during the shelf-life period and within 45 days. Three types of full fats yogurts have been analyzed (a) natural white (b) sweet white and (c) whole fruit - in two stages: t0 (first day of shelf-life) and t1 (end of shelf-life). The proteins have been analyzed by the Kjeldahl method and the amino acid profile by HPLC. In natural yogurt a significant increase of the amount of free amino acids has been observed during the period of shelf-life (97%). In the sweetened full fats and fruit yogurt, instead, there is a lower increase of respectively 33% and 39% In whole milk natural yogurt, based on our data, the proteolytic activity seems to persist during the entire period of the shelf-life and this can be considered an index of bacterial survival, especially of Lactobacillus delbrueckii subsp. bulgaricus during the marketing process.
The yogurt amino acid profile's variation during the shelf-life / A., Germani; R., Luneia; F., Nigro; V., Vitiello; Donini, Lorenzo Maria; DEL BALZO, Valeria. - In: ANNALI DI IGIENE MEDICINA PREVENTIVA E DI COMUNITÀ. - ISSN 1120-9135. - STAMPA. - 26:3(2014), pp. 205-212. [10.7416/ai.2014.1978.]
The yogurt amino acid profile's variation during the shelf-life.
DONINI, Lorenzo Maria;DEL BALZO, Valeria
2014
Abstract
To analyze the yogurt amino acid profile starting from marketing through the whole shelf-life. The evaluation of the proteolytic activity of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus, allows to deduce their vitality during the shelf-life period and within 45 days. Three types of full fats yogurts have been analyzed (a) natural white (b) sweet white and (c) whole fruit - in two stages: t0 (first day of shelf-life) and t1 (end of shelf-life). The proteins have been analyzed by the Kjeldahl method and the amino acid profile by HPLC. In natural yogurt a significant increase of the amount of free amino acids has been observed during the period of shelf-life (97%). In the sweetened full fats and fruit yogurt, instead, there is a lower increase of respectively 33% and 39% In whole milk natural yogurt, based on our data, the proteolytic activity seems to persist during the entire period of the shelf-life and this can be considered an index of bacterial survival, especially of Lactobacillus delbrueckii subsp. bulgaricus during the marketing process.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
