Aroma Investigation of New and Standard Apple Varieties Grown at Two Altitudes Using Gas Chromatography-Mass Spectrometry Combined with Sensory Analysis.

The aromatic profile of apples constitutes important information for the characterization and description of local products. Apple flavor is determined by perception in mouth and aroma; while the first is mainly defined by sugars and organic acids, aroma is a complex mixture of many volatile organic compounds (VOCs) whose composition is often specific to the variety. Headspace-solid phase microextraction gas chromatography coupled with mass spectrometry (HS-SPME-GC-MS) allows for the detection of detailed information of volatile constituents. In this study, eleven apple varieties (Braeburn, Fuji, Gala, Golden Delicious, Coop 39-Crimson Crisp®, Dalinette-Choupette®, Fujion, CIV323-Isaaq®, Coop43-Juliet®, SQ159-Natyra®, UEB32642-Opal®) grown in two pedoclimatic locations at different altitudes in South Tyrol (Italy) (ca. 225 m and ca. 650 m a.s.l.) were investigated. Thirty-eight VOCs were identified and combined with sensory analysis results (from 11 trained panelist) to characterize the aroma of new and standard apple varieties with a special focus on pedoclimatic location differences. The study shows strong diversification of the varieties based on their VOC profiles and sensory attributes, as expected. Moreover, investigating how the pedoclimatic location at different altitudes can influence the apple aroma profile, we identified twelve VOCs involved in these differences and provided a deeper investigation on how different altitudes can influence the apple aroma composition and perceptions combining the analytical and sensory parameters.

Deciphering the genetic control of fruit texture in apple by multiple family-based analysis and genome-wide association.

Fruit texture is a complex feature composed of mechanical and acoustic properties relying on the modifications occurring in the cell wall throughout fruit development and ripening. Apple is characterized by a large variation in fruit texture behavior that directly impacts both the consumer's appreciation and post-harvest performance. To decipher the genetic control of fruit texture comprehensively, two complementing quantitative trait locus (QTL) mapping approaches were employed. The first was represented by a pedigree-based analysis (PBA) carried out on six full-sib pedigreed families, while the second was a genome-wide association study (GWAS) performed on a collection of 233 apple accessions. Both plant materials were genotyped with a 20K single nucleotide polymorphism (SNP) array and phenotyped with a sophisticated high-resolution texture analyzer. The overall QTL results indicated the fundamental role of chromosome 10 in controlling the mechanical properties, while chromosomes 2 and 14 were more associated with the acoustic response. The latter QTL, moreover, showed a consistent relationship between the QTL-estimated genotypes and the acoustic performance assessed among seedlings. The in silico annotation of these intervals revealed interesting candidate genes potentially involved in fruit texture regulation, as suggested by the gene expression profile. The joint integration of these approaches sheds light on the specific control of fruit texture, enabling important genetic information to assist in the selection of valuable fruit quality apple varieties.

Performance of an Expert Sensory Panel and Instrumental Measures for Assessing Eating Fruit Quality Attributes in a Pear Breeding Programme.

Breeding programmes count on stable trained panels that support breeding evaluation selections. This work aimed to evaluate the performance of a small expert panel in the join IRTA-PFR breeding programme to validate its use in the sensory assessments of fruit pear genotypes during the selection process. A breeding F1 population of 80 pear seedlings from this programme was used. Descriptors and standard references used for sensory evaluations of pear attributes were previously defined by the four members of the expert panel. A General Procrustes Analysis (GPA) was applied to analyse the relations between instrumental and sensory traits. The results showed a good relationship between sensory attributes such as firmness and crispness with penetrometer measures. A high correlation was also found between sensory sourness and titratable acidity (TA). Panel performance was evaluated in terms of reproducibility, homogeneity, and panel consonance. The results indicated that the experts were very consistent and had a good performance. The work demonstrates, for the first time, that a small expert trained panel could be efficiently used in pear breeding programmes and allows for the selection process in a more economical and available way in contrast to the larger sensory panels conventionally used.

A simple and portable method for on-line texture measurement of Italian "Speck Alto Adige".

Texture is a relevant parameter for the assessment of cured ham's quality. In this study a rapid on-line instrumental technique for the measurement of the texture of pieces of cured smoked ham intended for sale as "Speck Alto Adige" PGI was developed. Speck samples were subjected to a compression test using a portable Shore A tester, and instrumental data were compared with conventional texture analyses (texture profile analysis and stress relaxation test) and with sensory evaluations. First, a hardness range in which a threshold value could be identified for the eligibility of 120 speck samples for the "Speck Alto Adige" PGI indication was established; afterwards, a Shore A hardness threshold value of 48 was defined based on measurements of more than 1000 samples. These findings may help manufacturers to determine the textural properties of Speck, based on a simple and rapid instrumental analysis.

High temperature reduces apple fruit colour via modulation of the anthocyanin regulatory complex.

The biosynthesis of anthocyanin in many plants is affected by environmental conditions. In apple (Malus × domestica Borkh.), concentrations of fruit anthocyanins are lower under hot climatic conditions. We examined the anthocyanin accumulation in the peel of maturing 'Mondial Gala' and 'Royal Gala' apples, grown in both temperate and hot climates, and using artificial heating of on-tree fruit. Heat caused a dramatic reduction of both peel anthocyanin concentration and transcripts of the genes of the anthocyanin biosynthetic pathway. Heating fruit rapidly reduced expression of the R2R3 MYB transcription factor (MYB10) responsible for coordinative regulation for red skin colour, as well as expression of other genes in the transcriptional activation complex. A single night of low temperatures is sufficient to elicit a large increase in transcription of MYB10 and consequently the biosynthetic pathway. Candidate genes that can repress anthocyanin biosynthesis did not appear to be responsible for reductions in anthocyanin content. We propose that temperature-induced regulation of anthocyanin biosynthesis is primarily caused by altered transcript levels of the activating anthocyanin regulatory complex.