Apple stands out as one of the main fruits processed worldwide, generating an immense volume of industrial by-products, collectively known as apple pomace. This material contain important levels of ...bioactive compounds that could be used in food and pharmaceutical products, answering to current demands regarding the incorporation of natural-based ingredients, generally preferred for their reduced side effects (contrarily to the observed with most artificial components).
The option for industrial by-products as source of bioactive compounds has evident economic advantages, counteracting the typically higher cost of biorefinery processes, when compared with the employment of artificial compounds. In addition, this approach is aligned with current circular economy premises, in the sense of using an industrial waste as the starting material to extract high added value compounds.
Apple pomace remaining from cider and juice production companies is as a striking example of an underutilized industrial by-product. In fact, most bioactive compounds (particularly phenolics) in apple are found in its peels, resulting to be more concentrated in pomace than in whole fruits. The major phenolic compounds in apple pomace (e.g. flavonoids, hydroxycinnamic acids, or di-hydrochalcones) are associated with health promoting activities, mainly based on their antioxidant, anti-inflammatory, and antimicrobial properties. Therefore, these compounds could have different food and/or pharmaceutical (e.g., in novel dermal formulations) applications. Besides bioactive compounds, apple pomace contains high levels of pectin, which could likewise be used (as a natural gelling agent) in newly developed formulations.
•Apple pomace is among the most abundant byproducts worldwide.•Bioactive and functional compounds in apple pomace were characterized.•Phenolics, triterpenoids and pectin hold great potential for different formulations.•The bioactivity of each compound was explored to assess its potential usefulness.•Apple pomace was validated as a competitive source of valuable nutraceuticals.
This study identifies and assesses the main contributors to the environmental impact of dehydrated apple snacks produced through the hot air drying method, which is the most common method for ...dehydrating food. The study aims to fill the gap of Life Cycle Assessment (LCA) studies regarding dehydrated apple snacks produced using the hot air drying method. A “cradle to gate” approach of an LCA is performed, including the apple production, storage and calibration, peeling and cutting, dehydration, and packaging stages. The inventory used is mainly primary data collected from a fresh and dehydrated apple snacks producer. The results show that the snack producer’s stages have a larger contribution to the majority of categories when compared to the fresh apple producer’s stages. The electricity consumption within the snack production and the use of liquefied petroleum gas in dehydration are shown to be the largest contributors to the majority of the impacts. However, apple production is also shown to have a relevant contribution to the impact categories due to the use of pesticides, fertilizers, diesel, and electricity.
Fire blight, caused by
, is one of the most devastating apple diseases. The selection of cultivars of low susceptibility and the study of the genetic mechanisms of the disease play important roles in ...fire blight management. The susceptibility level to fire blight was evaluated in 102 accessions originating from Asturias, a cider-producing region located in the north of Spain with a wide apple germplasm. Evaluations took place under quarantine conditions using artificial inoculations of grafted plants. The results revealed wide variation in susceptibility responses and low-susceptible cultivars were identified. In addition, 91 cultivars were genotyped using the Affymetrix Axiom
Apple 480 K SNP array to conduct genome-wide association studies (GWAS). A statistically significant signal was detected on chromosome 10 using the multi-locus mixed model (MLMM). Two genes were identified as major putative candidate genes: a TIR-NBS-LRR class disease protein and a protein containing a development and cell death (DCD) domain. The outcomes of this study provide a promising source of information, particularly in the context of cider apples, and set a starting point for future genetic and breeding approaches.
Rapid apple decline disease (RAD) has been affecting orchards in the USA and Canada. Although the primary cause for RAD remains unknown, viruses may contribute to the incidence or severity of the ...disease. We examined the diversity and prevalence of viruses in orchards affected by RAD in the Okanagan and Similkameen Valleys (British Columbia, Canada). Next-generation sequencing identified 20 previously described plant viruses and one viroid, as well as a new ilarvirus, which we named apple ilarvirus 2 (AIV2). AIV2 was related to subgroup 2 ilarviruses (42–71% nucleotide sequence identity). RT-PCR assays of 148 individual leaf samples revealed frequent mixed infections, with up to eight viruses or viroid detected in a single tree. AIV2 was the most prevalent, detected in 64% of the samples. Other prevalent viruses included three ubiquitous viruses from the family Betaflexiviridae and citrus concave gum-associated virus. Apple rubbery wood virus 1 and 2 and apple luteovirus 1 were also readily detected. The thirteen most prevalent viruses/viroid were detected not only in trees displaying typical RAD symptoms, but also in asymptomatic trees. When compared with reports from orchards affected by RAD in Pennsylvania, New York State, and Washington State, regional differences in relative virus prevalence were noted.
Many viruses occur in apple (
(Borkh.)), but no information is available on their seed transmissibility. Here, we report that six viruses infecting apple trees, namely, apple chlorotic leaf spot ...virus (ACLSV), apple green crinkle-associated virus (AGCaV), apple rubbery wood virus 2 (ARWV2), apple stem grooving virus (ASGV), apple stem pitting virus (ASPV), and citrus concave gum-associated virus (CCGaV) occur in seeds extracted from apple fruits produced by infected maternal trees. Reverse transcription polymerase chain reaction (RT-PCR) and quantitative RT-PCR (RT-qPCR) assays revealed the presence of these six viruses in untreated apple seeds with incidence rates ranging from 20% to 96%. Furthermore, ASPV was detected by RT-PCR in the flesh and peel of fruits produced by infected maternal trees, as well as from seeds extracted from apple fruits sold for fresh consumption. Finally, a large-scale seedling grow-out experiment failed to detect ACLSV, ASGV, or ASPV in over 1000 progeny derived from sodium hypochlorite surface sterilized seeds extracted from fruits produced by infected maternal trees, suggesting no detectable transmission via embryonic tissue. This is the first report on the seedborne nature of apple-infecting viruses.
The large number of cultivars belonging to the cultivated apple (Malus × domestica Borkh.) reflects an extremely wide range of variability, including for fruit quality traits. To evaluate some ...characteristics of fruit quality, 22 apple genotypes were selected from a collection of germplasms containing more than 600 accessions, based on different considerations, including the use of fruits (dessert, cooking, processing, juice, cider, multipurpose). The mean water content of the studied apple genotypes was 85.05%, with a coefficient of variation (CV) of 2.74%; the mean ash content was 2.32% with a CV of 22.1%, and the mean total soluble solids was 16.22% with a CV of 17.78%, indicating a relatively small difference between genotypes for these indices. On the contrary, relatively large differences were registered between genotypes for fruit weight, volume, and titratable acidity with means of 119.52 g, 155 mL, and 0.55% malic acid, and CVs of 35.17%, 34.58%, and 54.3%, respectively. The results showed that peel hardness varied between 3.80 and 13.69 N, the toughness between 0.2 and 1.07 mm, the flesh hardness between 0.97 and 4.76 N, and the hardness work between 6.88 and 27.84 mJ. The current study can emphasize the possibility of choosing the appropriate apple cultivars to cross in the breeding process and how future strategies can help apple breeders select breeding parents, which are essential key steps when breeding new apple cultivars. In addition, multivariate analysis has proven to be a useful tool in assessing the relationships between Malus genetic resources.
The leafhopper, Erythroneura sudra (Distant) is becoming a dominant insect pest, and usually can cause significant damage to fruit production in northern China. We studied the occurrence and density ...of E. sudra on three fruit tree species and its transcriptomic responses when it was fed on leaves of these tree species. A higher density and survival rate of E. sudra were recorded when it fed on leaves of peach (Amygdalus persica L.) (Rosales: Rosaceae) and cherry (Cerasus pseudocerasus Lindl) (Rosales: Rosaceae) than on apple (Malus domestica Mill) (Rosales: Rosaceae). Also, feeding on M. domestica induced the largest variation in transcriptomic profiles in E. sudra. In total, 166 genes were differentially expressed (89 upregulated and 77 downregulated) in E. sudra when it fed on M. domestica, compared to when it fed on the other two tree species. The upregulated genes were mainly related to 'response to oxidative stress', 'stress- resistance', and 'xenobiotic metabolic process'. The downregulated genes were mainly related to 'structural constituent of cuticle', 'biosynthetic process', and 'development regulation'. These results suggested that M. domestica significantly changed the expression of many genes and consequently caused lower occurrence and density of E. sudra. Such information could enhance our understanding of the leafhopper-host plant relationship. Additionally, it can contribute to the improvement of current control strategies for this pest.
The timing of the transition between endodormancy and ecodormancy remains uncertain. However, with advancements in phenology modelling, we can now fit models which allow for variable transitions ...between chilling and forcing models. Previous studies have primarily focused on single-cultivar parameterisation, and few have explored multi-cultivar comparative modelling. In this paper, we address this gap by evaluating three parameterisation approaches based on the recently developed PhenoFlex framework using a large flowering time dataset of twenty-six apple cultivars collected at the same location in England. The three parameterisation approaches were: cultivar-specific, group-specific with the groups derived using the K-means algorithm on mean bloom and variation of bloom dates, and a common model (for all twenty-six cultivars). The three PhenoFlex models fitted to each of three groups of cultivars based on their flowering time and the common model fitted to all cultivars achieved similar predictive performance, better than predictions using the average bloom date of each cultivar. The best approach to apply would depend on the amount of data present. The common model works best with large number of cultivars with small datasets (∼10 years), the mean flowering date grouped works best with medium numbers of datasets (∼20 years) and the cultivar-specific model should only be used when each cultivar has at least 30 years of data, however, it is more biased, so it is likely to predict bloom dates later than the observed bloom dates. Finally, the PhenoFlex model was shown to perform better than the StepChill model, where no overlapping is allowed between chilling and heat models. The result of this study indicates that the PhenoFlex model can be used to determine apple flowering time at the species level.
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•The PhenoFlex model reports lower apple chill (25.36) and heat (286.01) thresholds.•Multi-cultivar parameterisation can outperform individual cultivar parametrisation.•Cultivar-specific parameterisation results in inconsistent and bias predictions.
•An online optical sensing system was developed to detect apple qualities.•ILE-WSM method was proposed to complete the apple image segmentation.•NSR method was proposed to eliminate the scattering ...effects in the raw spectra.•ILE-WSM method was effective with the surface bruises detection accuracy of 97.3 %.•NSR method had better effective compare with other existing preprocessing methods.
An optical sensing system for the detection of surface bruises and the internal qualities of apples has been developed. Isohypse line extraction combined with marker constraint watershed segmentation (ILE-WSM), as a method to resolve the uneven brightness problem in apple images during bruise detection was investigated. The method has three steps: first, morphological filtering to reduce the random noise in the raw images; second, the ILE to locate the bruise position in the de-noised images; and finally, the WSM to complete the final image segmentation. For a 300 undamaged and bruised apples, the correct classification rate was 97.3 % using the ILE-WSM method, showing better segmentation ability than the Otsu method. For internal quality detection, the normalized spectral ratio (NSR) method has been proposed to correct the light scattering effects in the raw spectra. The NSR has the advantages of a simple calculation and high precision over the other methods. The final detection models for the apple soluble solids content (SSC) and dry matter content (DMC) were built on the key variables after selection by the competitive adaptive reweighted sampling (CARS) method. The root mean square error of the prediction dataset (RMSEP) and the correlation coefficient of the prediction dataset (Rp) of the final model prediction for the SSC and DMC were 0.412 % and 0.957 and 0.602 % and 0.937, respectively. The size of the whole system was 1600 mm × 500 mm × 1500 mm and the total time required to inspect each apple was 0.42 s. The optical sensing system can successfully be applied to apple surface bruise and internal quality detection.
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•Active films made with apple-based polymers carrying M. pulcherrima were developed.•The higher yeast viability was observed in films made with “apple residues.”•MC and “apple ...residues” films exerted high antifungal activity in vitro.•A coating made with “apple residues” was successfully applied as a coating on apples.•Active coatings reduced the growth of P. expansum and patulin content on apples.
The aim of this work has been to prevent the growth of Penicillium expansum on the surface of apples by means of the use of biocontrol agents in combination with edible coatings. For that, Metschnikowia pulcherrima yeast isolated from wild apples was incorporated in edible film matrices based on pectins, cellulose ethers with and without the addition of liquid culture medium (yeast extract and glucose) and apple pomace residues.
The viability and biocontrol activity of the yeast incorporated in the films were evaluated after film drying process and after being stored for 21 days at 10 °C. Furthermore, the matrix that exhibited the best results was applied as a coating on apples artificially inoculated with P. expansum in order to evaluate its antifungal activity against P. expansum during storage and to prevent the production of its mycotoxin, the patulin. M. pulcherrima remained viable in films after drying step and after 21 days storage, but viability depended on the matrix composition, being lower in pectin films and higher in apple pomace films. The highest antimicrobial activity in vitro was observed in methylcellulose films supplemented with yeast extract and glucose (YEG), and in apple pomace residues films, matrix which was therefore selected to be applied as coatings on apples inoculated with P. expansum. The results proved that bioactive coatings significantly reduce P. expansum growth and patulin production during storage. The results obtained in this work give added value to the apple industry residues which, in combination with apple isolated M. pulcherrima can be applied as coatings on apples to provide protection against blue mold and its mycotoxin as an alternative of postharvest disease management.
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