Structural and emulsion stabilizing properties of pectin rich extracts obtained from different botanical sources

Abstract

The presented research studied the emulsifying and emulsion stabilizing capacity of pectin samples isolated from different plant origin: apple, carrot, onion and tomato. The acid extracted pectin samples showed distinct structural properties. Specifically, apple pectin showed a high degree of methylesterification (78.41 ± 0.83%), carrot pectin had the lowest concentration of other co-eluted cell wall polymers, onion pectin displayed a bimodal molar mass distribution suggesting two polymer fractions with different molar mass and tomato pectin was characterized by a high protein content (16.

The Structure and Composition of Extracted Pectin and Residual Cell Wall Material from Processing Tomato: The Role of a Stepwise Approach versus High-Pressure Homogenization-Facilitated Acid Extraction

“…In the case of tomato, this DM is greatly dependent on the ripeness of the tomato [ 70 ]. The reported DM for acid-extracted pectin by Neckebroeck et al [ 44 ] was 54.3% and thus comparable to the value obtained for the AcEF. In the current study, red-ripe tomatoes which were not yet clearly softening were studied and immediately high-temperature-blanched to avoid any further structural changes of the pectin by enzymes, e.g., demethoxylation by pectin methylesterase.…”

“…Indeed, the Rha/UA ratio of the AcEF was in between the value for the WEF and CEF on the one hand and for the lAEF on the other hand, which also showed that acid conditions enabled extraction of more strongly interacting pectin together with more loosely bound pectin. The average MM determined by Neckebroeck et al [ 44 ] of tomato pectin extracted under acid conditions using the same conditions as in our study was around 523 kDa, which was almost double the result for the AcEF (270.3 kDa) in Table 1 . This discrepancy could be attributed to a different batch of tomatoes used.…”

“…As expected, UA is the most prominent among the monosaccharides characterized, indicating that the main polysaccharide present in the EFs was pectin. Neckebroeck et al [ 44 ] found a higher relative amount of Gal to Rha for nitric acid-extracted pectin, which was probably related to the different batch of tomato since the obtained Gal content for the AcEF was in line with the content of Gal obtained for the other EFs and also with the content in the AIR and the UFs (cfr. 3.3).…”

“…The value for the AcEF was in between the values obtained for the EFs of the chemical stepwise approach. In the WEF, CEF and AcEF, a small amount of Glc was found, which could be attributed to a small amount of co-extracted starch during the first step(s) of the extraction procedures [ 44 , 60 ]. Since the amount of starch in tomato decreases during ripening [ 60 ], the low value of Glc in these extracts is reasonable as tomatoes were used in their red-ripe stage.…”

“…After thawing, the blanched tomato slices were mixed in a laboratory blender (Waring Commercial, Torrington, CT, USA) two times for three seconds and subsequently filtered over a 1-mm sieve in order to remove peels and seeds [ 44 ]. The AIR was prepared based on the method by McFeeters and Armstrong [ 45 ].…”