Upcycling Rocha do Oeste Pear Pomace as a Sustainable Food Ingredient: Composition, Rheological Behavior and Microstructure Alone and Combined with Yeast Protein Extract

Abstract

This work explores the potential of Rocha do Oeste pear pomace to be used as a sustainable and healthy food ingredient. Moreover, the enrichment with yeast protein extract (YPE) may be useful to design innovative food products. The main goals of this study were to assess pear pomace concerning: (i) chemical composition and antioxidant capacity; (ii) rheology, texture, and microstructure characterization (alone or enriched with YPE), before and after heating. The results showed that pear pomace was a rich source of dietary fibers (74.5% DW), with phenolic compounds (3.9 mg chlorogenic acid equivalents/g dry weight), also presenting antiradical activity (3.90 μmol Trolox equivalents/g DW). Pear pomace showed a shear thinning behavior and a typical soft-gel behavior, which was not affected by YPE enrichment, thus suggesting that YPE did not affect pear pomace technological properties. Thermal treatment also did not alter pear pomace rheological properties. YPE addition induced a decrease in the apparent viscosity and a destabilizing effect, compared to the samples that were subjected to thermal processing. These results highlight the importance of pear pomace and the use of YPE for protein enrichment, opening new opportunities for their exploitation.

Characterization of the Effect of a Novel Production Technique for ‘Not from Concentrate’ Pear and Apple Juices on the Composition of Phenolic Compounds

“…As it is known, in apple, non-extractable compounds correspond to 6,7% of the total phenolic content [24], and these values are not very different for pear [25]. Fruits and vegetables may contain phenolic compounds in the form of non-extractable conjugates, soluble conjugates (such as glycosides and fatty acid esters), and extractable conjugates.…”

Bioactive Compounds of Portuguese Fruits with PDO and PGI

“…The municipalities of Bombarral, Cadaval, Caldas da Rainha, and Lourinhã are the main areas known for their extensive pear orchards, covering approximately 70% of the total cultivated area and production [61]. 'Pera Rocha do Oeste' PDO is characterized by its firmness, acidity, soluble solids content, color, high digestibility, nutritional value, and abundant content of antioxidant phenolic compounds [62]. The pear's skins, seeds, and flesh are composed primarily of sugars, fibers, pectins, other insoluble carbohydrates, minerals, organic acids, and The composition of total phenolic compounds in this variety is consistent with the value for other types of pears, with values ranging between 39.3 and 93.1 and averaging 66.2 mg GAE/100 g. Additionally, the vitamin C content was found to vary between 2.1 and 10.4 mg ascorbic acid/100 mL.…”

“…'Rocha' pear exhibited a superior concentration of total phenolics, with the predominant constituents being identified as chlorogenic, syringic, ferulic, and coumaric acids, as well as arbutin and (−)-epicatechin (Table 9). Furthermore, 'Rocha' pear outperformed the other varieties in antioxidant assays, specifically in the DPPH radical scavenging activity (Table 9, lowest IC50) and ferric-reducing power tests [13,62]. Santos et al [64] study fresh and dried 'Rocha' pears from five distinct geographical locations: Torres Vedras, Azueira, Bombarral, Cadaval, and Caria.…”

“…‘Pera Rocha do Oeste’ PDO is characterized by its firmness, acidity, soluble solids content, color, high digestibility, nutritional value, and abundant content of antioxidant phenolic compounds [ 62 ]. The pear’s skins, seeds, and flesh are composed primarily of sugars, fibers, pectins, other insoluble carbohydrates, minerals, organic acids, and phenolic compounds [ 62 ]. In 2019, 60% of the Portuguese production of ‘Rocha’ pear was exported [ 63 ].…”

Physicochemical Properties of Dried and Powdered Pear Pomace

“…Pear pomace (PP), which includes the peel, pulp, stem, core, and seeds remaining after industrial juice production, is known to contain 44 to 79% fiber on a dry weight basis, as well as organic acids, triterpenes, and polyphenols [11,12]. Fresh PP can contain up to twice as many polyphenolic compounds as the whole fruit, with levels reaching up to 18 g•kg −1 of fresh weight [13].…”