Effets Des Technologies Membranaires Sur Les Caracteristiques Physicochimiques Des Extraits De Fruits De La Passion (Passiflora Edulis)

The passion fruit or grenadilla is usually consumed in the form of juice and its pleasant intensive aroma and flavor make it an attractive element for the food industry. The objective of the present work is to determine the effects of membrane technologies such as tangential microfiltration and reverse osmosis on the physicochemical characteristics of passion fruit extracts. The characteristics of the various extracts were determined according to conventional methods. In addition, statistical methods were applied to the data collected in order to determine the effects of membrane technologies. The results showed a yield of 89.33% for the extraction of the microfiltered juice and a volume reduction factor of 16.75 for the concentrate. In addition, the microfiltration-concentration process significantly (p <0.05) influenced the physicochemical parameters of the extracts produced. Thus, tangential microfiltration made it possible to clarify the crude extract by changing from a turbidity of 89.23 ± 1.71 to 0.72 ± 0.02 NTU. It has also resulted in a significant decrease in pH and flavonoids contents. Principal component analysis confirmed the existence of differences between the extracts produced despite the various correlations between their characteristics. It revealed that the JB and CMFT extracts are characterized by their high pH and low density. On the other hand, the COI extract is characterized by its brix degree, viscosity, conductivity and high vitamin C content. In addition, reverse osmosis has the advantage of concentrating the compounds of interest of clarified juice with a concentration factor ranging from 2.15 to 9.39

Optimization of anthocyanin, flavonol and phenolic acid extractions from<em> Delonix regia</em> tree flowers using ultrasound-assisted water extraction

International audienceFlowers of Delonix regia trees from Ivory Coast are traditionally macerated in water to prepare beverages with beneficial health properties mainly due to their polyphenolic contents. Different maceration procedures, mimicking the traditional process, were compared on the basis of polyphenol content followed by HPLC-DAD analysis. Under optimized maceration ratio (R = plant sample weight/maceration media volume), plant extractions were compared, including acidified-water-based media and assisted-ultrasound or stirring extraction procedures. Diffusion kinetics of polyphenol families (anthocyanins, flavonols and phenolic acids) were followed by HPLC and lead to find optimum ratio (R = 1/100). Flavonol contents were 28.5, 31, and 33.5 μmol g−1 (expressed as quercetin equivalent), using acidified-water (0.01N) media with sulphuric or citric acids. Anthocyanin and phenolic acid contents were within the same range for these water media (5.6 μmol g−1 as cyanidin equiv. and 27.5 μmol g−1 as gallic acid (GA) equiv., respectively). Ultrasound-assisted procedure shortened maceration time (three times shorter) but did not show higher level of total polyphenol than stirring-assisted procedure (39 μmol g−1 GA equiv.). This eco-friendly and low-cost extraction process will provide to African people, with safer quality and longer availability, polyphenol-rich bio-product

Effects of Temperature and Other Operational Parameters on <em>Chlorella vulgaris</em> Mass Cultivation in a Simple and Low-Cost Column Photobioreactor

International audienceMass production of microalgae worldwide, and even more so in developing countries, is strongly contingent upon the availability of economical and efficient photobioreactors (PBRs) that are amenable for use in resource-limited environments. Such options are limited. This work assesses the effects of temperature, CO2 enrichment, and mixing by air + CO2 bubbling on Chlorella vulgaris biomass production in a simple, low-cost 84-L column PBR. Cultivation at 25, 30, and 35 °C in a batch process showed that biomass production was negatively affected above 30 °C. Specific growth rates at each temperature were 0.75, 0.76, and 0.63 day(-1), respectively, with batch productivities of 70.50, 81.67, and 35.83 mg L-1 day(-1). While a relatively low CO2/air ratio (1 %) seemed beneficial during the early stages of cultivation, higher concentrations were required to maintain growth rate and achieve higher biomass concentrations around 1000 mg L-1. Cultivation with air + CO2 bubbling rates of 100, 200, and 400 L h(-1) led to specific growth rates (and batch productivities) of 0.64 day(-1) (59.58 mg L-1 day(-1)), 0.74 day(-1) (81.67 mg L-1 day(-1)), and 0.80 day(-1) (86.67 mg L-1 day(-1)), respectively. The results indicate that high biomass productivities of C. vulgaris can be obtained up to 30 °C with moderate (2 %) to high (10 %) CO2 in a fairly simple PBR

Polyphenol Characterization in Red Beverages of Carapa procera (D.C.) Leaf Extracts

The red aqueous beverages of Carapa procera (D.C.) leaf extracts were investigated for their polyphenol contents using HPLC-DAD, HPLC-ESI-MS, and semipreparative HPLC. Polyphenols were extracted, clarified, and concentrated using a multistep process including ultrasound-assisted extraction (UAE), cross-flow microfiltration (CFM), and reverse osmosis (RO). On the basis of analytical and semipreparative chromatographic techniques, 12 phenolic compounds were identified and quantified for the first time: 2 anthocyanins (cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside), 5 phenolic acids (protocatechuic, the three caffeoylquinic isomers, and coumaroylquinic acid), and 5 flavonols (quercetin 3-O-rutinoside, quercetin 3-O-galactoside, quercetin 3-O-glucoside, quercetin aglycone, and kaempferol 3-O-rutinoside). From the concentrated extract, it was possible to recover for anthocyanins (28.4 ± 0.3 µmol L −1 cyanidin equivalents) the two glycosides of cyanidin, for flavonols (1587 ± 3 µmol L −1 quercetin equivalents) the two glycosides of quercetin and kaempferol, and for phenolic acids (3650 ± 10 µmol L −1 gallic acid equivalents) chlorogenic and protocatechuic acids