Utilisation de l'isopropanol pour l'extraction de la matière grasse de produits laitiers et pour l'estérification subséquente des acides gras

Wolff, Robert Lee; Fabien, Robert J.

doi:10.1051/lait:198913

Cited by 46 publications

(20 citation statements)

References 14 publications

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“…Fatty acid methyl esters (FAMEs) of milk were obtained by alkaline transesterification, following the method described by Wolff and Fabien (1989). Afterward, FAMEs were extracted with 1 mL of hexane.…”

Section: Methodsmentioning

confidence: 99%

Effects of dietary sources of vegetable fats on performance of dairy ewes and conjugated linoleic acid (CLA) in milk

Castro

Manso

Jimeno

et al. 2009

Small Ruminant Research

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ARTICLE INFO ABSTRACT Keywords:Vegetable fats Milk performance Milk CLA Dairy eweTwo experiments were carried out to study the effects of supplementing the ration of lactating ewes with vegetable fats (sunflower oil, SO or hydrogenated palm oil, HPO; HIDROPALM®) on diet digestibility, milk yield and milk composition, and on the concentration of the conjugated linoleic acid (CLA) C18:2 cis-9 trans-11 and C18:l trans-11 (vaccenic acid, VA) and other main fatty acids in milk fat. Treatments involved a control diet, without added oil, and 2 diets supplemented with either 12g/kg SO or 12g/kg HPO on a dry matter (DM) basis. In the first experiment, 6 non-pregnant, non-lactating Lacaune ewes were used following a 3 x 3 replicated Latin Square design. Addition of vegetable fat supplement to the diet increased digestibility of DM, organic matter (OM) and crude protein (CP), but did not affect that of the ether extract (EE), neutral detergent fibre (NDF) or acid detergent fibre (ADF). In the second experiment, 60 Lacaune dairy ewes mid-way through lactation (120 ±12 days in milk, 0.98 ± 0.03 kg/day average milk yield) were divided into three equalsized groups each of which was assigned to one of the three experimental diets for4 weeks. Compared with the control treatment, supplementation with HPO increased milk yield and energy-corrected milk. But neither vegetable fat supplement modified percentages of fat and protein in milk. Supplementation with HPO increased C14:l, C16:l and C16:0 content and reduced C18:0 and C18:l cis-9 content in milk fat. Supplementation with SO increased the VA content in milk fat by 36% and that of cis-9 trans-11 CLA by 29% in comparison with the control diet. Supplementation with HPO led to milk fat with 15% more cis-9 trans-11 CLA than control milk. In conclusion, adding a moderate dose of HPO or SO to the diets increased CLA concentration in milk fat. Nevertheless, supplementation with SO was more effective than HPO in increasing CLA concentration in milk fat and reducing the atherogenicity index, improving milk quality from the human health standpoint.

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Section: Methodsmentioning

confidence: 99%

Effects of dietary sources of vegetable fats on performance of dairy ewes and conjugated linoleic acid (CLA) in milk

Castro

Manso

Jimeno

et al. 2009

Small Ruminant Research

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“…Total lipids were extracted from creams by means of hexane-isopropanol (3:2, v/v) according to Wolff and Fabien's [52] and Wolff and Castera-Rossignol's [51] methods. The milk fat extraction procedure was adapted with a centrifugation step.…”

Section: Fat Extraction and Phospholipid Quantificationmentioning

confidence: 99%

Heat treatment of cream affects the physicochemical properties of sweet buttermilk

Gassi¹,

Famelart²,

Lopez³

2008

Dairy Sci. Technol.

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-The objective of this work was to investigate the effect of heat treatment of sweet creams on the physicochemical properties of sweet industrial buttermilks. Creams with three different heat treatments: low, medium and high, were churned and the corresponding buttermilks were characterised. Furthermore, buttermilks were renneted and centrifuged to obtain insoluble pellets and supernatants. The physicochemical properties such as the particle size measured by laser light scattering and composition of creams, buttermilks, pellets and supernatants were determined and compared. Buttermilk had a composition close to that of skim milk but it contained more phospholipids (PL): 958 (± 137) mg·kg −1 , compared with 120 mg·kg −1 in milk. The heat treatment induced a significant decrease in soluble protein contents in creams, buttermilks and soluble fractions as well as an increase in the buttermilk PL/fat ratio, and an increase in supernatant protein and total solids. Buttermilk and supernatant particle sizes ranged from 0.03 to 200 μm, with a maximum at 130 nm, which may correspond to small milk fat globules, phospholipid vesicles or protein aggregates. Fat and PL in buttermilks were recovered in supernatants. The use of buttermilk enzymatic coagulation combined with centrifugation may constitute a means to fractionate milk PL.buttermilk / phospholipid / protein / heat treatment / particle size crèmes, babeurres, sérums et culots, ainsi que la taille des particules ont été déterminées et comparées. L'augmentation de l'intensité des traitements thermiques conduit à une diminution significative de la concentration en protéines solubles dans les crèmes, babeurres et surnageants, à une augmentation du ratio phospholipides/matière grasse du babeurre, ainsi que de l'extrait sec et de la matière azotée totale des surnageants. Les babeurres avaient des compositions proches de celle du lait écrémé, mais avec une concentration plus importante en phospholipides : 958 (± 137) mg·kg −1 contre 120 mg·kg −1 . Les particules des babeurres et des surnageants avaient un diamètre compris entre 0,03 et 200 μm avec un maximum centré sur 130 nm. Ces particules pourraient correspondre à des globules gras de petite taille, des vésicules de phospholipides et/ou des agrégats de protéines. La totalité des lipides contenus dans les babeurres a été retrouvée dans la fraction soluble des surnageants. Techniquement, une coagulation enzymatique du babeurre suivie d'une centrifugation pourrait constituer un moyen de fractionnement des phospholipides.babeurre / phospholipide / protéine / traitement thermique / taille de particule

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“…25 ul, of the c1ear hexane solution and 100 pg of heptadecanoic acid as internaI standard were transferred into teflon-lined screw capping tube and isopropylated according to Wolff and Fabien [20]. The fatty acid isopropyl esters (FAIPE) were extracted by 2 mL of hexane and analyzed by gas chromatography.…”

Section: Totalfatty Acids (Tfa)mentioning

confidence: 99%

Characterization of aroma compounds in the volatile fraction of soft goat cheese during ripening

Quéré

Aimar

Riaublanc³

et al. 1998

Lait

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-A traditional Sainte-Maure soft cheese was analyzed from 2 days to 31 days of ripening for ils gross composition, total and free fatty acid distribution and the aroma cornpounds in the volaiile fraction of cheese, which were studied by gas chromatography coupled with mass spectrometry. Cheese ripening was characterized by a very low level of casein proteolysis, 5%, which was hydrolyzed in low molecular mass peptides, and by a high lipolysis level, up to 6% of free to total fatty acids at the end of ripening. The volatile fraction of cheese was studied using gas chromatography coupled with mass spectrometry. Among the 38 compounds identified in the volatile fraction, seven were characterized by olfactometry as having a specifie cheese or goat cheese aroma. They were: hexanoic, octanoic, nonanoic, decanoic 3-methylbutanoic, 4-methyloctanoic and 4-ethyloctanoic. Sorne acids were present at levels higher than their threshold value (TV) even in 2-day cheeses, while sorne others only reached their TV in the 31-day cheeses, showing that the flavor of ripened cheeses was different from that of fresh cheeses. © InralElsevier, Paris.

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Utilisation de l'isopropanol pour l'extraction de la matière grasse de produits laitiers et pour l'estérification subséquente des acides gras

Abstract: fat -extraction -isopropyl esters -gas Iiquid chromatography -response factor -low caloriespread

Cited by 46 publications

References 14 publications

Effects of dietary sources of vegetable fats on performance of dairy ewes and conjugated linoleic acid (CLA) in milk

Effects of dietary sources of vegetable fats on performance of dairy ewes and conjugated linoleic acid (CLA) in milk

Heat treatment of cream affects the physicochemical properties of sweet buttermilk

Characterization of aroma compounds in the volatile fraction of soft goat cheese during ripening

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