Yves Lozano

A-type proanthocyanidins from pericarp of Litchi chinensis

Abstract A tannin extract was isolated from freeze-dried litchi pericarp (Litchi chinensis). HPLC analysis, after thioacidolysis reaction, revealed that this tannin fraction consisted of epicatechin units linked by both A- and B-type interflavonoid bonds. The calculated average degree of polymerization, considering the presence of A-type linkages, was 6.4. Characterization of oligomeric and polymeric procyanidins was performed using electrospray ionization mass spectrometry. Numerous oligomers containing one or more A-type interflavanoid linkages were detected. A regular repartition of the number of A-type linkages for each polymer length (e.g. from 2 to 7 for DP17 with mostly 4 A-type linkages) was observed. The average number of A-type linkages also increased with the DP, the predominant species containing one A-type linkage (denoted 1A) from DP2 to 5, 2A from DP6 to 10, 3A from DP11 to 15 and 4A from DP16 to 20. The highest DP was estimated at 22, with predominantly 5–6 A-type interflavanoid linkages.

Triglyceride and fatty acid compositions in the mesocarp of Persea americana during fruit development

Abstract The moisture and lipid contents and fatty acid and triglyceride (TG) compositions of mesocarp of developing avocado fruits ( Persea americana , Lula variety) were studied. The moisture content decreased steadily with increasing lipid content during the 12–39 weeks after flowering (WAF). In the early stage (12 WAF), the fatty acids and TGs represent the minor amount of the lipid fraction (13%). As the fruits developed, the fatty acid and TG contents increased to 88 and 85 %, respectively, at 36 WAF. Thereafter, the fatty acid level remained unchanged and the TG level decreased to 72 %. No significant change in fatty acid balance was observed from 16 to 39 WAF. On the other hand, the linoleyl oleyl palmitin + dioleyl palmitolein content increased while the triolein and dioleylpalmitin content decreased as the fruits matured. The fatty acid and TG composition of Lula variety were markedly different from those of other varieties.

Anthocyanin Characterization of Pilot Plant Water Extracts of Delonix regia Flowers

Following the development of new applications of pilot plant scale extraction and formulation processes for natural active bioproducts obtained from various under-utilized tropical plants and herbs, we have manufactured water-extracts from Delonix regia flowers, grown in Ivory Coast. These extracts, which contain polyphenols, are traditionally home made and used as healthy bioproducts. They are reddish-coloured due to the presence of anthocyanins. The three major anthocyanins in these extracts have been characterized. The molecular structures were confirmed by LC-SM analysis. Amongst them, two are described for the first time in Delonix regia.

Enzymatic degradation of cell wall polysaccharides from mango (Mangifera indica L.) puree

Ripe mango puree (Smith cultivar) was treated with fungal polysaccharidases containing pectinolytic, hemicellulolytic, and cellulolytic activities for 2 h at 50 degrees C. A loss of 30% of the cell wall material (CWM) was measured. CWM polysaccharides were hydrolyzed to varying degrees: 88, 65, and 65% of, respectively, galacturonic acid-, arabinose-, and rhamnose-containing polymers were hydrolyzed, whereas 50% of cellulose was degraded. After 30 min of treatment, the ethanol precipitation test on the serum was negative, indicating that pectic substances were rapidly hydrolyzed. Oligogalacturonic acids (degree of polymerization, 1-12) were observed in the serum. A viscosity drop of 90% was measured after 2 h, confirming the dominant role of pectic substances in puree viscosity.