Suitability of buttermilk for fermentation with Lactobacillus helveticus and production of a functional peptide-enriched powder by spray-drying.

AIM: To ferment buttermilk, a low-cost by-product of the manufacture of butter, with a proteolytic strain of Lactobacillus helveticus, to enhance its value by the production of a functional peptide-enriched powder. METHODS AND RESULTS: Buttermilk was fermented with Lact. helveticus 209, a strain chosen for its high proteolytic activity. To enhance the release of peptidic fractions, during fermentation pH was kept at 6 by using NaOH, Ca(CO)(3) or Ca(OH)(2). Cell-free supernatant was recovered by centrifugation, supplemented or not with maltodextrin and spray-dried. The profile of peptidic fractions released was studied by RP-HPLC. The lactose, Na and Ca content was also determined. The powder obtained was administered to BALB/c mice for 5 or 7 consecutive days, resulting in the proliferation of IgA-producing cells in the small intestine mucosa of the animals. CONCLUSIONS: Buttermilk is a suitable substrate for the fermentation with Lact. helveticus 209 and the release of peptide fractions able to be spray-dried and to modulate the gut mucosa in vivo. SIGNIFICANCE AND IMPACT OF THE STUDY: A powder enriched with peptides released from buttermilk proteins, with potential applications as a functional food additive, was obtained by spray-drying. A novel use of buttermilk as substrate for lactic fermentation is reported.

Growth of Lactobacillus paracasei A13 in Argentinian probiotic cheese and its impact on the characteristics of the product.

The growth capacity of probiotic Lactobacillus paracasei A13, Bifidobacterium bifidum A1 and L. acidophilus A3 in a probiotic fresh cheese commercialized in Argentina since 1999 was studied during its manufacture and refrigerated storage at 5 degrees C and 12 degrees C for 60 days. Additionally, viable cell counts for probiotic bacteria in the commercial product are reported for batch productions over the last 9 years. L. paracasei A13 grew a half log order at 43 degrees C during the manufacturing process of probiotic cheese and another half log order during the first 15 days of storage at 5 degrees C, without negative effects on sensorial properties of the product. However, a negative impact on sensorial characteristics was observed when cheeses were stored at 12 degrees C for 60 days. Colony counts in the commercial product showed variations from batch to batch over the last 9 years. However, colony counts for each probiotic bacterium were always above the minimum suggested. Growth capacity of L. paracasei A13 in cheese during manufacturing and storage, mainly at temperatures commonly found in retail display cabinets in supermarkets (12 degrees C or more), would make it necessary to re-evaluate its role as possible probiotic starter and the consequences on food sensorial characteristics if storage temperature during commercial shelf life is not tightly controlled.

Congestive and hemorrhagic lesions of duodenal mucosa. Critical evaluation.

In 34 patients congestive, hemorrhagic lesions were detected by endoscopy. It was considered that trauma was not responsible for these lesions. In all of the patients except four, histology showed no inflammatory reaction. Most of the patients were hypochlorhydric and one was achlorhydric. Serum gastrin levels appeared within a normal range under fasting and stimulated conditions. Twenty-four patients were followed up two years later. Only 1 patient had developed a duodenal ulcer. The endoscopic picture appeared unmodified in the reendoscopized patients. It is concluded that the hemorrhagic lesions of the duodenum may result from local vascular disorders without any inflammation.