Physicochemical Fingerprint of “Pera Rocha do Oeste”. A PDO Pear Native from Portugal

Abstract

“Pera Rocha do Oeste” is a pear (Pyrus communis L.) variety native from Portugal with a Protected Designation of Origin (PDO). To supply the world market for almost all the year, the fruits are kept under controlled storage. This study aims to identify which classical physicochemical parameters (colour, total soluble solids (TSS), pH, acidity, ripening index, firmness, vitamin C, total phenols, protein, lipids, fibre, ash, other compounds including carbohydrates, and energy) could be fingerprint markers of PDO “Pera Rocha do Oeste”. For this purpose, a data set constituting fruits from the same size, harvested from three orchards of the most representative PDO locations and stored in refrigerated conditions for 2 or 5 months at atmospheric conditions or for 5 months under a modified atmosphere, were selected. To validate the fingerprint parameters selected with the first set, an external data set was used with pears from five PDO orchards stored under different refrigerated conditions. Near infrared (NIR) spectroscopy was used as a complementary tool to assess the global variability of the samples. The lightness of the pulp; the b* CIELab coordinate of the pulp and peel; and the pulp TSS, pH, firmness, and total phenols, due to their lower variability, are proposed as fingerprint markers of this pear.

Clean Label “Rocha” Pear (Pyrus communis L.) Snack Containing Juice By-Products and Euglena gracilis Microalgae

“…The obtained pH value for the puree fraction (4.60 ± 0.079) agrees with Pedro et al (22) results for this pear variety. None of the remaining fractions have significantly (p > 0.05) different pH values between them and the puree.…”

“…As expected, given the insoluble fiber predominance in "Rocha" pear (22), pomace fraction shows significantly (p < 0.05) the highest content of total and insoluble dietary fiber (3.52 ± 0.100 g 100 g −1 and 3.43 ± 0.110 g 100 g −1 , respectively)-puree centrifugation concentrates most of the suspended particles (which represents most of the insoluble fiber) in the pomace, as well as some soluble dietary fiber, leaving the other liquid fractions with only dietary fiber residues. Therefore, puree processing concentrates the dietary fiber in the pomace, the most suspended solids concentrated fraction, making it interesting to develop satiating and functional products.…”

“…Concerning ascorbic acid results, the visible difference between pear purees from both these studies and the ones from Pedro et al (22) is certainly due to the addition of this acid to preserve fruit purees from oxidation. The fact that the crossflow filtration had a negative impact on the resulting fractions was expected and can be explained by the unfavorable thermal conditions and the contact with the atmospheric oxygen, as it may have happened with Mai (57) who also crossflow filtrated several fruit juices, and with Mrad et al (78) who dried pears (vitamin C thermal degradation started at 30 • C).…”

“…It is one of the most relevant fruits in Portugal, not only in terms of production area but also in economic and exportation terms (in 2019, 60% of the production was exported). It is characterized by its firm pulp, high digestibility, interesting content in dietary fiber [2.3% (w/w)], and high amounts of ferulic acid, in comparison with other varieties ( 22 , 23 ). It is also one of the fruits widely processed and studied by SUMOL+COMPAL, an important Portuguese fruit juice company that showed an obvious interest in the knowledge and valorization of by-products resulting from the production of pear juices, in particular pomaces resulting from juice clarification steps.…”

Increase of Calcium in ‘Rocha’ Pear (Pyrus communis L.) for Development of Functional Foods

“…This study supportes that pre-harvest sprays of Ca do not affect colorimetric parameters, and the same was observed in 'Conference' pears like previously mentioned [12]. Addicionally for 'Rocha' pears stored for 2 to 5 months, L ranged from 66.69 to 79.55, and a* and b* coordenates varied between −12.87 to 5.64 and 39.17 to 45.52, respectively [28]. The values from our study fall within this ranges, especially considering that during storage pears color can change from a proeminence of green to yellow [16,18], explaining the a* coordinate difference.…”