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Zanabria R.,University of Guelph | Zanabria R.,Canadian Research Institute for Food Safety CRIFS | Tellez A.M.,Kraft Foods Inc. | Griffiths M.W.,University of Guelph | And 2 more authors.
Dairy Science and Technology | Year: 2014

The milk fat globule membrane (MFGM), the material surrounding milk fat globules, is not only interesting from a technological standpoint but it also shows great potential as a health ingredient, as it exerts cytotoxic and apoptotic effects against colon cancer cells. Although the effects of milk processing on the MFGM composition and functionality are well documented, less is understood on how processing may affect its bioactivity. This study aimed to determine if heating can affect the antiproliferative capacity of the MFGM. To do so, MFGM was extracted from milk heated at 80 °C for 10 min, as this temperature/time regime is known to cause extensive protein-protein interactions with changes in the processing functionality of milk. Two cell lines, whose morphological features are representative of two different stages of colon carcinogenesis (HT-29 and Caco-2), were used to test the antiproliferative capacity of MFGM isolates obtained either from untreated or heated milk. Cell proliferation analysis showed a similar dose-dependent decrease of DNA synthesis in both cell lines exposed to 6.25-200 μg of MFGM protein.mL-1, isolated from unheated milk. The heat treatment diminished the efficacy of the MFGM isolates, as only the highest concentrations of MFGM tested following heating showed a significant effect on cell proliferation. The decreased ability of MFGM isolates to affect the carcinoma cell proliferation was attributed to changes in composition, mainly phospholipid losses. Changes to the supramolecular structure of the MFGM caused by heating may also have played a role. This work demonstrates the importance of processing history in assessing the biological functionality of MFGM. © 2014 INRA and Springer-Verlag France.

Zanabria R.,University of Guelph | Tellez A.M.,University of Guelph | Tellez A.M.,Canadian Research Institute for Food Safety CRIFS | Griffiths M.,University of Guelph | And 2 more authors.
Food and Function | Year: 2013

A native milk fat globule membrane (MFGM) isolate obtained from raw milk was assessed for its anticarcinogenic capacity using a colon cancer cell line (HT-29). To prevent microbial contamination and eliminate the presence of lipopolysaccharide (LPS) in the milk used for MFGM isolation, the milk was obtained from the mammary glands of cows using a catheter. Cell proliferation assays demonstrated a reduction of exponentially growing cancer cells of up to 53%, expressed as DNA synthesis (BrdU test), after 72 h stimulation with 100 μg of MFGM protein per mL. Using a similar MFGM concentration, the sulforhodamine B assay resulted in 57% reduction of cell density after 48 h incubation. This bioactivity was comparable to that of known anticancer drugs, 0.1 mM melphalan and 20 μM C2-ceramide, which achieved a cell division reduction of 25 and 40%, respectively, under the same experimental conditions. The toxic effect of the MFGM extracts on HT-29 cells was confirmed by the significant reduction in lactate dehydrogenase enzyme (LDH) by the residual viable cells. An increase of caspase-3 activity (up to 26%) led to the conclusion that MFGM has an apoptotic effect on HT-29 cancer cells. © 2013 The Royal Society of Chemistry.

Xu S.,University of Guelph | Walkling-Ribeiro M.,University of Guelph | Walkling-Ribeiro M.,Canadian Research Institute for Food Safety CRIFS | Griffiths M.W.,University of Guelph | And 2 more authors.
Journal of Dairy Science | Year: 2015

The present work evaluated the effect of processing on the antiproliferative activities of milk fat globule membrane (MFGM) extracts. The antiproliferative activity on human adenocarcinoma HT-29 cells of untreated MFGM extracts were compared with those extracted from pasteurized cream, thermally treated cream, or cream subjected to pulsed electrical field (PEF) processing. The PEF with a 37 kV/cm field strength applied for 1,705. μs at 50 and 65°C was applied to untreated cream collected from a local dairy. Heating at 50 or 65°C for 3. min (the passage time in the PEF chamber) was also tested to evaluate the heating effect during PEF treatments. The MFGM extracted from pasteurized cream did not show an antiproliferative activity. On the other hand, isolates from PEF-treated cream showed activity similar to that of untreated samples. It was also shown that PEF induced interactions between β-lactoglobulin and MFGM proteins at 65°C, whereas the phospholipid composition remained unaltered. This work demonstrates the potential of PEF not only a means to produce a microbiologically safe product, but also as a process preserving the biofunctionality of the MFGM. © 2015 American Dairy Science Association.

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