Comparison of alcohol precipitation and membrane filtration effects on sugar beet pulp pectin chemical features and surface properties

in Food Hydrocolloids (2007), 21(2), 245-255

Two different procedures, alcohol precipitation with washing (APW) and a 10 kD MWCO membrane ultrafiltration with diafiltration (UF-DF), for pectin recovering and purification from crude aqueous extracts ... [more ▼]

Two different procedures, alcohol precipitation with washing (APW) and a 10 kD MWCO membrane ultrafiltration with diafiltration (UF-DF), for pectin recovering and purification from crude aqueous extracts were investigated. The results showed that the yield, purity, chemical, and physicochemical features of isolated pectins depended upon the type of procedure used. The APW technique gave a higher pectin yield, and the isolated pectin contained more neutral sugars, more proteins, and more ash but less galacturonic acids than the 10 kD membrane UF-DF one. The weight-average molar mass of the APP was lower and its emulsifying properties slightly better than those of the UFPR10. Molar mass distribution of APP or UFPR10 showed two distinct pectin fractions peaks, which were separated in high-MW and low-MW pectin fractions using a 50kD MWCO membrane. The high-MW fractions exhibited poor emulsifying and emulsion stabilizing abilities whereas the low-MW fractions displayed a much higher emulsifying ability than the initial pectin fractions. Therefore, it was inferred that the ability of beet pectin to be an effective emulsifier and/or emulsion stabilizer was greatly dependent on its weight-average molar mass. (c) 2006 Elsevier Ltd. All rights reserved. [less ▲]

Isolation And Chemical Evaluation Of Carob (Ceratonia Siliqua L.) Seed Germ

in Food Chemistry (2007), 102(4),

Use of a Plackett-Burman experimental design to examine the impact of extraction parameters on yields and compositions of pectins extracted from chicory roots (Chicorium intybus L.)

in Journal of Agricultural and Food Chemistry (2006), 54(19), 7167-7174

Chicory root pectin was isolated by acid extraction followed by alcohol precipitation. Because the extraction conditions have important effects on the features of pectins, an experimental design was used ... [more ▼]

Chicory root pectin was isolated by acid extraction followed by alcohol precipitation. Because the extraction conditions have important effects on the features of pectins, an experimental design was used to study the influence of 17 different extraction parameters on yield and composition of pectin: pH, temperature, time of extraction, solid/liquid ratio, and different pretreatments of the pulps before extraction. Twenty extractions were conducted and examined for their significance on yield and sugar content using the Plackett-Burman factorial design. The acid extraction of chicory roots resulted in an average yield of 11% containing 86% of sugars. It was found that extraction temperature, time, protease pretreatment, water purity, and water washing of pulps significantly affected yield and pectin composition with an increase of yield and purity of pectin in harsher extraction conditions. [less ▲]

Maintenance threonine requirement and efficiency of its use for accretion of whole-body threonine and protein in Atlantic salmon (Salmo salar L.) fry.

in British Journal of Nutrition (2006), 95(2), 234-45

Eighteen groups of seventy Atlantic salmon (Salmo salar L.) fry (initial mean body weight 0.8 (sd 0.01) g) were fed on semi-purified diets containing graded levels of l-threonine (Thr) in 15 litres ... [more ▼]

Eighteen groups of seventy Atlantic salmon (Salmo salar L.) fry (initial mean body weight 0.8 (sd 0.01) g) were fed on semi-purified diets containing graded levels of l-threonine (Thr) in 15 litres aquaria at a temperature of 14.5+/-1 degrees C. Doses of Thr represented 1, 31, 41, 51, 62, 72, 83 and 93 % of its ideal level for optimum protein deposition. Indispensable amino acids other than Thr were included in the same proportion (on a g/16 g N basis) as in the Atlantic salmon fry whole-body carcass. Following 36 d of feeding and a 36 h fast, fry were killed for whole-body protein and amino acid analysis. Weight gain (r2 0.98), protein accretion (r2 0.97), and Thr accretion (r2 0.97) were linear (P<0.01) functions of Thr intake. Slope of the Thr accretion regression line showed that the efficiency of Thr utilisation above maintenance was 76 %. At zero Thr intake, fry lost 5.4 mg Thr/kg body weight0.75 per d. The Thr maintenance requirement was 7.2 mg/kg body weight0.75 per d and the Thr requirement for growth was 66 mg for 1 g protein deposition. Increasing doses of Thr resulted in increased (P<0.05) concentrations of histidine and lysine, and decreased concentrations of isoleucine in whole-body protein. The maintenance need for Thr represented 13.4 % of the total need for Thr. The data suggest that efficiency of Thr utilisation above maintenance is constant at all levels of Thr intake between 1 and 93 % of the level required for optimum protein deposition. [less ▲]

Strategy for the qualitative and quantitative analysis of crop syrup containing enzymatically produced Isomaltooligosaccharides known as emerging prebiotics

Poster (2006)

Isomaltooligosaccharides (IMOs) are non-digestible oligosaccharides, considered as prebiotics and therefore aim to selectively feed probiotics indigenous to the human colon. Recent data obtained in human ... [more ▼]

Isomaltooligosaccharides (IMOs) are non-digestible oligosaccharides, considered as prebiotics and therefore aim to selectively feed probiotics indigenous to the human colon. Recent data obtained in human subjects, support the involvement of dietary oligosaccharides in physiological processes in the different intestinal cell type and also outside the gastrointestinal tract (e.g. hormone production, lipid and carbohydrate metabolism). IMOs consists of glucose monomers linked by at least one α-1-6, or in a lower proportion α -1-3 (nigerose family) or α -1-2 (kojibiose family) glucosidic linkages. In our case they are produced enzymatically from corn starch. It results in a very complex mixture with molecules characterized at the same time by their DP value (from 2 to ~20), linkages types (α-1-2, 3 or 6) and the proportion and position of each type of linkage (only α -1-6 or combined types). The challenge of this study was to find a qualitative and quantitative method to characterize the syrups. In a subsequent study, every unidentified peak could be determined by NMR or Mass spectrometry. Three different chromatographic methods have been tested and compared over their selectivity, sensibility, robustness, applicability and their quantitative power. The HPLC-RID (Refractive Index Detector) used with a Prevail Carbohydrate column (Alltech), adapted for carbohydrates with a certain value of DP, appear to be poorly selective due to the obligation of working in isocratic conditions. The HPLC-ELSD (Evaporating Light Scattering Detector) used with the same column gave a very good separation upon the DP as the Prevail accepts a wide range of solvant changing and even a separation of the different DP 2 molecules. The sensibility was also improved due to the stability of the baseline. The quantitative analysis is a bit more awkward due to the relatively limited linear portion of the calibration curve. High-performance Anion Exchange Chromatography coupled with Pulsed Amperometric Detection (HPAEC-PAD) appeared to deserve a special mention, since it provides selective separation and sensitive detection. In fact, this technique is the only chromatographic one to separate with effectiveness homologue molecules having a difference only in their DP (up to high DPs) or linkage types. This is due to the separation mode based on the difference in ionic force of the sugars in alkaline conditions (mainly due to the DP and the structure of the molecule). However, during the detection, the electrochemical behavior of carbohydrates can be affected by molecular weight as well as by structural differences giving rise to different response factors; as a consequence, HPAEC-PAD is not generally considered as suitable for quantitative studies of complex mixtures of oligosaccharides. In this work a methodological approach is presented in order to get a quantitative response through a rigorous methodology for our IMOs. It also opens the way to the theoretical determination of the response factor for the homologue molecules in relation with their structure and DP. [less ▲]

Synthese enzymatique d’esters de sucre au départ d’huiles végétales

Poster (2005, October 14)

Sugar esters lipase mediated synthesis from vegetable oils

Poster (2005, September)

Improvement of lupin seed valorisation by the pig with the addition of alpha-galactosidase in the feed and the choice of a suited variety.

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2005), 9(4), 225-235

Three experiments were conducted to assess whether an a-galactosidase supplement improved the utilisation of lupin seeds by growing and finishing pigs and to determine the best lupin variety in presence ... [more ▼]

Three experiments were conducted to assess whether an a-galactosidase supplement improved the utilisation of lupin seeds by growing and finishing pigs and to determine the best lupin variety in presence of a-galactosidase. In experiment 1, three iso-nitrogen (iso-N) and iso-net energy (iso-NE) diets containing 15% of soybean meal (SBM diet) or 20% of lupin seeds (Lupinus albus var. Arès), with or without an a-galactosidase supplement (‘lupin’ and ‘lupin + a-gal’ diets, respectively), were ingested by 12 pigs fitted with a caecal canula, following a completely randomized experimental design. The ileal digestibility of a-galactosides tended to increase with the lupin + a-gal diet. Nitrogen retention of pigs eating the SBM diet was similar to that of those fed with the lupin + a-gal diet and higher than that observed for pigs given the lupin diet. The results suggested that a-galactosides are the main anti-nutritional factors in lupin seeds for pigs. The same diets were investigated in a production trial (experiment 2) involving 48 pigs with a live weight of between 30 and 105 kg. The fattening period was similar for the SBM and lupin + a-gal diets (107 d) and longer for the lupin diet (123 d). With the lupin diet there was a lower average daily gain (ADG, -16%) and a higher food conversion ratio (FCR, + 8%) than with the two other diets. The backfat of pigs fed with lupin-based diets contained fewer polyunsaturated fatty acids (PUFA) and had a lower w6/w3 ratio. In experiment 3, three iso-N and iso-NE diets containing different varieties of lupin (Lupinus albus cv Lublanc and Amiga; Lupinus angustifolius cv Boltensia) and an a-galactosidase supplement were investigated in 12 pigs fitted with a caecal canula, as in Exp. 1. The results showed that the digestible protein supply by the Boltensia diet was higher than in the others. However, the Boltensia variety led to a higher urinary N excretion than the Lublanc variety. The results obtained with Amiga were intermediate. Consequently, the utilisation of ingested and digested proteins was relatively high with the Lublanc diet, intermediate with the Amiga diet and low with the Boltensia diet. The results suggested that the Lublanc variety was better adapted for pig feed that contained an a-galactosidase supplement. [less ▲]

Hemolytic activity of new linear surfactin analogs

Poster (2005)

Study of synthesis and surface activity of inulin lauric esters.

Poster (2004, February 11)