Articles scientifiques

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06 juin 2017

Analysis of plastic residues in maple sap and syrup collected from tubing systems sanitized with isopropyl alcohol

Auteurs : Luc Lagacé, Carmen Charron et Mustapha Sadiki.

Cet article est disponible seulement en anglais (Heliyon, Volume 3, Issue 5, May 2017, Article e00306). Le numéro de référence (Digital Object Identifier (DOI)) est le :  10.1016/j.heliyon.2017.e00306.

A plastic tubing system operated under vacuum is usually used to collect sap from maple trees during spring time to produce maple syrup. This system is commonly sanitized with isopropyl alcohol (IPA) to remove microbial contamination colonizing the system during the sugar season. Questions have been raised whether IPA would contribute to the leaching of plastic residues in maple sap and syrup coming from sanitized systems. First, an extraction experiment was performed in the lab on commercial plastic tubing materials that were submitted to IPA under harsh conditions. The results of the GC-MS analysis revealed the presence of many compounds that served has target for further tests. Secondly, tests were done on early and mid-season maple sap and syrup coming from many sugarbushes using IPA or not to determine potential concentrations of plastic residues. Results obtained from sap and syrup samples showed that no quantifiable (< 1–75 μg/L) concentration of any plastic molecules tested was determined in all samples coming from IPA treated or not treated systems. However, some samples of first sap run used as a rinse solution to be discarded before the season start and that were coming from non sanitized or IPA sanitized systems, showed quantifiable concentrations of chemical residue such as ultraviolet protector (octabenzone). These results show that IPA can be safely used to sanitize maple sap collection system in regards to the leaching of plastic residues in maple sap and syrup and reinforced the need to thoroughly rinse the tubing system at the beginning of the season for both sanitized and non sanitized systems. (4010110)

18 juillet 2016

Viability of probiotic bacteria in a maple sap beverage during refrigerated storage

Auteurs : Joseph Lupien-Meilleur, Denis Roy et Luc Lagacé.

Cet article est disponible seulement en anglais (LWT - Food Science and Technology, Volume 74, December 2016, Pages 160–167). Le numéro de référence (Digital Object Identifier (DOI)) est le : 10.1016/j.lwt.2016.07.045.

There is an increasing demand for non-dairy probiotic foods made from raw materials. This study assessed the ability of maple sap concentrate diluted to 2, 5, and 8 ºBx to maintain the viability of probiotic bacteria inoculated at 108 and 1010 CFU/portion of 40 mL and stored for 12 weeks at 4 _C. Three two-strain and one three-strain combinations of Lactobacillus rhamnosus R0011, Lactobacillus helveticus R0052, and Bifidobacterium animalis subsp. lactis BB12 were analyzed. Survival was monitored by selective plate counting and viability was assessed by quantitative PCR following propidium monoazide treatment (PMA-qPCR). Results showed a lower survival of mixed cultures of R0052 and BB12 inoculated at 1010 CFU/portion than survival values obtained at 108 CFU/portion. Culturable and viable counts from sap inoculated at 1010 CFU/portion were significantly lower in sap diluted at 2 ºBx for every combination, highlighting the protective role of sap components at higher total soluble solids concentration. The ability of maple sap concentrate to maintain probiotic viability was readily and accurately determined by PMA-qPCR. According to this study, concentrated maple sap was able to maintain high viable and survival counts of carefully selected probiotics, demonstrating its potential as fluid for the production of a probiotic beverage. (432-4080026)

10 mars 2015

Biochemical composition of maple sap and relationships among constituents

Auteurs : Luc Lagacé, Simon Leclerc, Carmen Charron et Mustapha Sadiki.

Cet article est disponible seulement en anglais (Journal of Food Composition and Analysis, Volume 41, August 2015, Pages 129–136). Le numéro de référence (Digital Object Identifier (DOI)) est le : 10.1016/j.jfca.2014.12.030.

Maple sap is a product of great economic value with a variable composition. Samples of maple sap were collected at different periods of the 2007 and 2008 seasons in various locations in Quebec (Canada). The aim of the study was to establish a typical chemical composition of maple sap by analyzing a large number of maple sap samples. Multiple factor analysis was also performed to help establish relationships among compounds. Results confirm that total soluble solids and sucrose concentration were higher near mid-season. The concentration of specific organic acids in sap could depend on the sugarbush (malic acid) or could be influenced by microbial activity (acetic and lactic acid). Phenolic compounds of interest were present mainly at the beginning of the season and decreased as the season progressed. The concentrations of the main minerals (K, Ca and Mg) increased over the sap flow season and the presence of calcium and magnesium seemed highly correlated. These results will help in establishing an update of mean values and ranges for many components of maple sap. 2015 Elsevier Inc. All rights reserved. (439 - 4010028)


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