Fuji Apple Research Articles

Metabolomic analysis of the browning and browning inhibition pulp of Fuji apple at different ripening stages

Apples at different ripening stages display distinct processing properties and browning characteristics in products. This study aimed to identify differential metabolites and metabolic pathways of browning pulp and browning inhibition pulp of Fuji apple across four ripening stages (M1–M4), corresponding to days after full bloom (DAFB: 148, 155, 162, and 171). We investigated the physicochemical characteristics, browning-related enzyme activities, and metabolomic profiles of apples at the four stages, revealing defensive metabolic changes associated with browning throughout ripening. Specifically, the browning rate in apples increased with ripening, peaking before declining in the late stages, and exhibited positive correlations with activities of polyphenol oxidase (PPO), peroxidase (POD), and catalase (CAT), and negative correlations with superoxide dismutase (SOD), phenylalanine ammonia-lyase (PAL), and H2O2 levels. Metabolomic profiling identified 315, 393, and 243 distinct metabolites in fresh control (FC), browning pulp (BR), and browning-inhibited pulps (CM) of apple at the four ripening stages, respectively. KEGG enrichment analysis revealed that FC and BR of the four ripening apples were differentiated by phenylpropanoid biosynthesis, while CM was featured by flavonoid biosynthesis. The characterized differential metabolites in BR were changed to α-linolenic acid metabolism with ripening, while those in CM were from flavonoid and phenylpropanoid biosynthesis. Furthermore, the in-depth analysis revealed 40 significantly differential metabolites associated with amino acid, nucleotide, coenzyme, and vitamin metabolism, potentially modulating the stress-responsive cellular redox balance. This research provides critical insights for browning prevention in the processing of fruits at various ripening stages.

A systematic analysis of scan matching techniques for localization in dense orchards

In recent years, different methods have been studied to determine machinery position within a grove, as an alternative for complementing GNSS (global navigation satellite system) information in cases where GNSS signal is occluded. Such a situation can be observed when agricultural machinery travels under dense foliage or on the slopes of mountains. Scan matching techniques arise as a possible solution for localizing the machinery, complementing the absence of the GNSS signal when necessary. However, since key points are difficult to obtain in heterogeneous, unstructured and non-rigid environments (such as orchard plants), the performance of scan matching techniques often decreases in agricultural environments. This paper suggests dividing the point clouds into horizontal and vertical segments to improve the performance of scan-matching methods in orchards. It also examines the best way for registered frames to overlap. We validate the analysis with extensive experimentation in a Fuji apple orchard. The results show that the cumulative localization error in scan matching techniques can be notoriously decreased with selective parts of the orchard, by up to 60%. The experimentation performed herein suggests that the proposed methodology can complement the GNSS navigation in a middle-long path.

Extraction of apple pomace polyphenols using natural deep eutectic solvents: A sustainable approach

To effectively utilize apple pomace resources, we extracted apple pomace polyphenols using natural deep eutectic solvent (NADES) as the medium, with a solvent-to-solid ratio of 50 mL/g, for a duration of 120 min. Compared to conventional extraction solvents (ethanol and methanol), four NADES significantly enhanced the extraction efficiency of polyphenols from apple pomace. Notably, NADES 1 (betaine: urea = 1:1, 30% water) and NADES 2 (betaine: malic acid = 1:1, 30% water) exhibited superior extraction capabilities, with maximum values reaching 5.245 ± 0.124 mg GAE/g pomace and 5.157 ± 0.164 mg GAE/g pomace, respectively, in Qinguan apple pomace. Both solvents reached their maximum extraction efficiency within 120 min, with NADES 1 achieving a maximum extraction amount of 4.8325 mg GAE/g and NADES 2 achieving 5.3039 mg GAE/g from Fuji apple pomace. NADES 1 and NADES 2 were more efficient in extracting monophenols such as quercetin, rutin, gallic acid, and procyanidin, whereas organic solvents (methanol and ethanol) were more effective for monophenols like methyl gallate and phlorizin. Furthermore, polyphenol extracts obtained using NADES from Fuji apple pomace displayed varying levels of antibacterial effectiveness, with NADES 4 (glucose: lactic acid = 1:5, 60% water) and NADES 2 showing superior efficacy against Escherichia coli and Staphylococcus aureus. This comprehensive study not only demonstrated the potential of NADES in extracting polyphenols from apple pomace but also highlighted their applicability as natural preservatives in the food industry.

Optical properties related to cell wall pectin contribute to determine the firmness and microstructural changes during apple softening

The modification of cell wall pectin is a major contributing factor to apple softening, associated with intensive variations of firmness and microstructure. Thus, a better understanding of the relationship between fruit optical properties, firmness, 3D microstructure and pectin is important for improving the optical detection of apple firmness. This work explored the optical properties in the wavelength range of 430 – 1650 nm related to cell wall pectin during apple softening, in order to better determine their firmness and 3D microstructural changes. An automatic single integrating sphere system was used to quantify absorption coefficient (μa) and reduced scattering coefficient (μs′). Micro-CT imaging, SEM and TEM were used to quantify the porosity, cell numbers, cell volume, volume fraction and microstructure of Fuji apples during storage. Firmness, pectin fractions, soluble solids content (SSC), titratable acid content (TAC), and moisture content were also measured. Results showed that depolymerization of pectin substances induces an increase in porosity (r = 0.97) and modification of cellular structure, leading to a decrease in firmness (r = 0.90). The reduction in firmness and cell numbers exhibited a strong positive correlation with both μa in the range of 1000 – 1650 nm and μs′ between 430 and 1000 nm with mean r of 0.88–0.96, whereas increases in covalent-soluble pectin (CSP) and porosity displayed a negatively correlated with these bands. The linear relationship indicates that Vis-NIRS at 980 nm could better predict apple firmness than μa or μs′ alone, with a coefficient of determination R2 of 0.97. Our findings suggest that the mechanism of optical technology for detecting apple firmness may be the interaction between tissue structure and pectin on μs′ and μa.

Impact of overhead evaporative cooling, canopy location, sunlight exposure, inoculation level, region, and growing season on the survival of generic Escherichia coli on in-field Fuji apples.

The survival of inoculated Escherichia coli on Fuji apples in Washington State orchards was studied, considering evaporative cooling, canopy location, year, and region, with the examination of sunlight exposure and inoculation levels in year 2. Rifampicin-resistant E. coli was applied to Fuji apples. Initial concentrations for the high-inoculation study were 7.4±0.3 log10 CFU per apple and 3.4±0.3 log10 CFU per apple for the low-inoculation study. Enumeration of E. coli was conducted at 0, 2, 10, 18, 34, 42, 58, 82, 106, and 154 h after inoculation. Results were analyzed using Tukey's honest significance difference test and a log-linear model. Log-linear, Weibull, and biphasic models characterized E. coli die-off patterns for high and low inoculations. The application of evaporative overhead cooling water did not significantly influence E. coli survival on Fuji apples; inoculation level and sunlight exposure were significant factors in a log-linear model. Escherichia coli decreased by 5.5±1.3 and 3.3±0.4 log10 CFU per apple for high and low-inoculated apples, respectively, by 154 h. The biphasic model best explained the die-off pattern for high and low-inoculated Fuji apples. Overhead evaporative cooling, a useful fruit quality practice, did not impact the survival of generic E. coli on Fuji apple surfaces. The significant impact of sunlight exposure and inoculation levels on die-off highlights the importance of ultraviolet radiation in risk reduction and the need for various inoculum concentrations in preharvest field studies.

Enhanced composite Co-MOF-derived sodium carboxymethyl cellulose visual films for real-time and in situ monitoring fresh-cut apple freshness

Natural biopolymers have extensively applications in intelligent food packaging due to their renewable nature, easy availability, environmental-friendly, low-cost and excellent processibility. Recently, the integration or embedding of nanocomposites on polymer substrates to improve the multi-faceted performance of packaging materials has attracted widespread attention. Herein, the irregular spherical Co-based metal-organic framework (Co-MOF) loaded with phenol red (PR) and bromothymol blue (BTB) were fabricated, resulting in absorbed nanocomposites Co-MOF/PR and Co-MOF/BTB. Afterward, the nanocomposites were integrated into a sodium carboxymethyl cellulose (CMC-Na) substrate to prepare a CO2-responsive packaging material (CMC-Na/PR/Co-MOF and CMC-Na/BTB/Co-MOF) for real-time and in-situ monitoring apple freshness. The synthesis of Co-MOF and the hydrogen-bonding interactions between MOF and pigments adsorption were confirmed. The advantages exhibited by the film with adding Co-MOF, including excellent hydrophobicity and water resistance, improved time-temperature stability and mechanical properties, were explored. Notably, the Co-MOF-based composite film exhibited enhanced UV–visible barrier, anti-migration performance of pigment, and thermal stability. Finally, a significant linear response (R2 = 0.9923 and 0.9781) between the total color difference values (ΔE) of Co-MOF-based film and hardness and total soluble solids (TSS) of fresh-cut Fuji apples at 4 °C was demonstrated, respectively. These findings indicate the significant potential of CMC-Na-based composite film containing multifunctional MOF nano-filler as a visual monitoring system, which will pave the way for fresh-cut fruit intelligent packaging.

Scaling up gaseous chlorine dioxide (ClO2) treatment in the cold storage of fresh apples

Novel interventions are needed to mitigate microbial risks, like Listeria monocytogenes, before shipping fresh apples to retail markets. Batch gaseous chlorine dioxide (ClO2) in-storage treatments were conducted to assess the inactivation of Listeria innocua, reduction of spoilage microorganisms, and changes in quality. Gaseous ClO2 was generated using equal amounts of dry precursors inside the modified commercial refrigerator with 82 kg and 330 kg apples for pilot and semi-industrial scale experiments, respectively. A cocktail of L. innocua was spot inoculated on the calyx of fresh Fuji apples and treated with an initial ClO2 input of 1.2 g of each precursor/kg of produce at a pilot scale for 30 d and semi-industrial scale for 90 d. Headspace ClO2 concentrations, temperature, and relative humidity were measured during the batch treatments. Reductions of 1.4±0.2 and 1.2 log CFU/mL of Listeria innocua were achieved by pilot-scale and semi-industrial scale trials, respectively. The presence of spoilage microorganisms was not significantly (P>0.05) impacted, and apples displayed no signs of deterioration. This study confirms that ClO2 can significantly inhibit foodborne pathogens, such as Listeria, during prolonged cold storage and reduce the risk of contamination for apple growers.

The physicochemical components, amino acids, organic acids, phenolic compounds and antioxidant capacity of apple ciders: According to geographical origin and altitude of Fuji apple

This study aimed to analyze the physicochemical parameters, amino acids, organic acids, total phenols, total flavonoids and antioxidant capacity of apple ciders fermented with Fuji apple from different regions. The results showed that there are differences in the composition and quality characteristics of ciders fermented with Fuji apple from different regions. The apple ciders fermented with Fuji apple from 11 different producing areas were divided into three categories by cluster heat map analysis. The samples belonging to category I are from Zhaotong. Category II comprises samples from Changli, Weihai, Xingcheng, and Qingyang, while category III includes samples from Liangshan, Yuncheng, Luochuan, Aksu, Jinzhong, and Lingbao. The altitude of the apple production area has an impact on the quality of the apples, consequently affecting the distinctive characteristics of the final apple cider. This research aims to provide a theoretical basis for the development and production of high-quality apple ciders.

A computer vision system for apple fruit sizing by means of low-cost depth camera and neural network application

AbstractFruit size is crucial for growers as it influences consumer willingness to buy and the price of the fruit. Fruit size and growth along the seasons are two parameters that can lead to more precise orchard management favoring production sustainability. In this study, a Python-based computer vision system (CVS) for sizing apples directly on the tree was developed to ease fruit sizing tasks. The system is made of a consumer-grade depth camera and was tested at two distances among 17 timings throughout the season, in a Fuji apple orchard. The CVS exploited a specifically trained YOLOv5 detection algorithm, a circle detection algorithm, and a trigonometric approach based on depth information to size the fruits. Comparisons with standard-trained YOLOv5 models and with spherical objects were carried out. The algorithm showed good fruit detection and circle detection performance, with a sizing rate of 92%. Good correlations (r > 0.8) between estimated and actual fruit size were found. The sizing performance showed an overall mean error (mE) and RMSE of + 5.7 mm (9%) and 10 mm (15%). The best results of mE were always found at 1.0 m, compared to 1.5 m. Key factors for the presented methodology were: the fruit detectors customization; the HoughCircle parameters adaptability to object size, camera distance, and color; and the issue of field natural illumination. The study also highlighted the uncertainty of human operators in the reference data collection (5–6%) and the effect of random subsampling on the statistical analysis of fruit size estimation. Despite the high error values, the CVS shows potential for fruit sizing at the orchard scale. Future research will focus on improving and testing the CVS on a large scale, as well as investigating other image analysis methods and the ability to estimate fruit growth.

New Progress in Intelligent Picking: Online Detection of Apple Maturity and Fruit Diameter Based on Machine Vision

In the realm of automated apple picking operations, the real-time monitoring of apple maturity and diameter characteristics is of paramount importance. Given the constraints associated with feature detection of apples in automated harvesting, this study proposes a machine vision-based methodology for the accurate identification of Fuji apples’ maturity and diameter. Firstly, maturity level detection employed an improved YOLOv5s object detection model. The feature fusion section of the YOLOv5s network was optimized by introducing the cross-level partial network module VoVGSCSP and lightweight convolution GSConv. This optimization aimed to improve the model’s multiscale feature information fusion ability while accelerating inference speed and reducing parameter count. Within the enhanced feature fusion network, a dual attention mechanism combining channel and spatial attention (GAM) was introduced to refine the color and texture feature information of apples and to increase spatial position feature weights. In terms of diameter determination, the contours of apples are obtained by integrating the dual features of color and depth images within the target boxes acquired using the maturity detection model. Subsequently, the actual area of the apple contour is determined by calculating the conversion relationship between pixel area and real area at the current depth value, thereby obtaining the diameter of the apples. Experimental results showed that the improved YOLOv5s model achieved an average maturity level detection precision of 98.7%. Particularly noteworthy was the detection accuracy for low maturity apples, reaching 97.4%, surpassing Faster R-CNN, Mask R-CNN, YOLOv7, and YOLOv5s models by 6.6%, 5.5%, 10.1%, and 11.0% with a real-time detection frame rate of 155 FPS. Diameter detection achieved a success rate of 93.3% with a real-time detection frame rate of 56 FPS and an average diameter deviation of 0.878 mm for 10 apple targets across three trials. Finally, the proposed method achieved an average precision of 98.7% for online detection of apple maturity level and 93.3% for fruit diameter features. The overall real-time inference speed was approximately 56 frames per second. These findings indicated that the method met the requirements of real-time mechanical harvesting operations, offering practical importance for the advancement of the apple industry.

Effects of chitosan combined with microbes on blue mold of apples

Investigation on the inhibitory effect of chitosan combined with antagonistic bacteria on pathogenic fungi, at different concentrations on Penicillium expansum were studied in vitro and in vivo with Japanese Red Fuji apples. The chitosan solution with the concentration of 2% had the strongest resistance to Penicillium expansum and blue mold decay without affecting the growth of Bacillus amyloliquefaciens BA-16-8. Both the bacterial suspension and cell-free fermentation liquor of Bacillus amyloliquefaciens BA-16-8 could inhibit Penicillium expansum, and the former is superior to the latter in effect. Bacillus amyloliquefaciens BA-16-8 combined with chitosan can inhibit the activity and toxin-producing ability of Penicillium expansum. Bangladesh J. Bot. 53(1): 25-32, 2024 (March)

Fuji apple ( Malus domestica Borkh. cv. Red Fuji) pomace extracts as a source of antimicrobial and antioxidant polyphenols

This study aimed to assess the antibacterial and antioxidant properties of both crude polyphenol extract (CPE) and purified polyphenol extract (PPE) obtained from Fuji apple pomace. The antibacterial capacity of both extracts against Staphylococcus aureus was investigated by evaluating the inhibition zones, minimum bactericidal concentrations (MBC), growth curves and bacterial morphology of S. aureus treated with CPE or PPE, as well as the performance in simulated food systems. The antioxidant activity of CPE or PPE was assessed using the ABTS radical scavenging and ferric reducing antioxidant power (FRAP) assays. The results showed that PPE exhibited potent antibacterial activity against S. aureus, which was further confirmed by the bacterial morphology. It was revealed that PPE only exerted strong antibacterial effect in starch-based food system while CEP did not show such effect in all systems. The results of the ABTS and FRAP assays indicated that both PPE and CPE possess strong antioxidant activity, from which PPE showed much higher capacity than that of CPE. Therefore, PPE from Fuji apple pomace can be used as a novel antibacterial agent for food preservation and natural antioxidant for functional food and nutraceutical products.

Research of ordinal model fusion based apple grading

Near infrared spectrum has been applied for the rapid non-destructive prediction and classification of the internal soluble solids content (SSC) of apples, due to its rapid, non-destructive and non-polluting nature. However, current apple grading methods do not make full use of the orderliness relationship existing in the apple grading labels. Therefore, ordinal model is introduced in the issue of apples grading based on the internal SSC. In details, the orderliness in the classification model is considered and ordinal regression is combined with apple classification model to establish ordered partition neural network and ordinal regression extreme learning machine, respectively. Meanwhile, to address the problems of poor applicability of single prediction model and the grading uncertainty associated with compulsory segmentation of grading boundaries, a Gaussian mass function generating method is proposed based on the distance between the predicted ordinal class labels and the real grading boundaries, and the multiple models can be fused through the Dempster combination rule, making a fuller description of the uncertainty problem on ordinal class labels prediction, providing a research basis for online non destructive testing grading of apples. Finally, the multiple model fusion process is fully demonstrated by simulation examples, the grading accuracy of Yantai Red Fuji apples is also improved than single ordinal model.

Study of the Effects of Spraying Non-Bagging Film Agent on the Contents of Mineral Elements and Flavonoid Metabolites in Apples

There has been growing interest in examining the potential of non-bagging patterns due to the decline of fruit inner quality and the increase in labor force cost and ecological pollution. Spraying a non-bagging film agent is an important method for non-bagging cultivation. This paper aims to study the effects of non-bagging film agents on the contents of mineral elements and flavonoid metabolites in apple fruits and determine the feasibility of this method. Fuji apples were used as the sample material and treated individually with two non-bagging film agents, namely, humic acid film (ABM) and Pirrio calcium film (CAM). Also, two control groups, namely, the clear water spraying without bagging group (CK) and the bagging group (TCK), were set in this study to measure the contents of mineral elements and flavonoid metabolites in these apples. Compared with those two control groups, the spraying treatment groups with two kinds of non-bagging film agents present a significant difference between their total contents of mineral elements, with the total content of mineral elements of apples in the ABM treatment group being 1.36 times the content of apples in the CK group. In terms of the flavonoid metabolites, only Astragalin, Tiliroside, Homoplantaginin, Phlorizin, Apigenin, Hesperidin, Oroxin A, and Kaempferol present significant differences in their proportions in apples, and there are no significant differences among the proportions of other compounds. Individual spraying of two kinds of non-bagging film agents can significantly increase the total contents of mineral elements in apples, with slight effects on the contents of flavonoid metabolites in these fruits. Therefore, both film agents can be used for cultivating Fuji apples.

The Effect of Nitrogen Reduction and Applying Bio-Organic Fertilisers on Soil Nutrients and Apple Fruit Quality and Yield

In this study, we investigated the effect of partially substituting inorganic nitrogen with bio-organic fertiliser on the ‘Tianhong2’ Fuji apple planting in Xinjiang. Bio-organic fertiliser was applied, and nitrogen was reduced by 20% (T2), 40% (T3), and 60% (T4) during the blooming and fruit expansion periods with conventionally fertilised fields used as control (T1); soil nutrient, soil enzyme activity, leaf nutrients, fruit quality, and yield were measured. The total nitrogen (TN), total phosphorus (TP), total potassium (TK), total calcium (TCa), available phosphorus (AP), available potassium (AK), and soil organic matter (SOM) contents, as well as the soil catalase (S-CAT), soil uretrase (S-UE), soil saccharase (S-SC), and soil nitrate reductase (S-NR) activities, significantly increased in the experimental soils compared with those in T1. In addition, TP, TCa, and total magnesium (TMg) content in apples significantly increased. Compared to T1, the T2 and T3 treatments significantly improved the fruit yield and quality, increasing the sugar–acid ratio, soluble protein, soluble sugar, peel carotenoid, and anthocyanin content and reducing peel chlorophyll content. The brightness (L*), red–green axis (a*), yellow–blue axis (b*), colour intensity (C), and tone (h°) values changed. The yield per hectare and nitrogen fertiliser partial productivity values were significantly increased. Overall, the T2 treatment resulted in the best outcome for the Yili area. In conclusion, partially substituting inorganic nitrogen with bio-organic fertiliser can effectively increase soil and leaf nutrient content and improve fruit yield and quality.

저온 저장 후지 사과의 과피와 과육 중 파이토케미컬 함량의 상관관계

This study determined the relationships between the total anthocyanin content in apple skin and the total polyphenols, flavonoids, proanthocyanidins, and soluble solids contents in the flesh of cold-stored Fuji apples. Total anthocyanin content in apple skin ranged from 0.130±0.005 mg CE/g fw to 0.262±0.028 mg CE/g fw, and the overall average was 0.200±0.008 mg CE/g fw. The total polyphenolic compounds in the flesh was ranged from a 4.283±0.141 mM GAE/g fw to 8.207±0.234 mM GAE/g fw, and the average content was 6.275±0.177 mM GAE/g fw. The total flavonoid content ranged from 4.510±0.080 mM QE/g fw to 2.467±0.458 mM QE/g fw, and the average total flavonoid content was about 3.586 mM QE/g fw. The total proanthocyanidin content was relatively high, ranging from 3.475±0.577 mM EE/g fw to 6.816±0.277 mM EE/g fw, and the soluble solid in the flesh was about 12 °Brix to 14 °Brix. The DPPH radical scavenging activity of extracts from apple flesh ranged from 66.36% to 94.99%, and the ascorbate equivalent concentration was 0.482 mM. The ABTS radical scavenging activity was 99.12% to 99.9%, indicating a higher inhibitory activity than the DPPH inhibitory activity, and the ascorbate equivalent concentration was 0.486 mM. The correlation between the total anthocyanin and total polyphenolic compounds was y = 15.192x + 3.2169 (R2=0.2748), but the concentration of total polyphenolic compounds increased when the total anthocyanin content was increased. The correlation equation of total anthocyanin with total flavonoids was y = 15.18x + 0.5555 (R2=0.6226), with total proanthocyanin was y = 14.918x + 2.3422 (R2=0.3372), and with soluble solid was y = 10.558x + 11.126 (R2=0.1925), indicating that the correlation of total anthocyanin with total flavonoid was higher than that with soluble solid.

Promotion of Thermal Inactivation Treatment of Apple Polyphenol Oxidase in the Presence of Trehalose.

Trehalose is known to protect enzymes from denaturation. In the present study, we observed promotion of apple polyphenol oxidase (PPO) inactivation in a trehalose solution with thermal treatment. Crude PPO from Fuji apple was mixed with either sucrose or trehalose solutions, then the samples treated at 25 or 65 °C. In the presence of trehalose, PPO activities were markedly decreased upon treatment at 65 °C with increasing trehalose concentration. Furthermore, the reduction in PPO activity in the presence of trehalose was proportional to storage time after thermal treatment and thermal treatment time. Comparing PPO activities between treatment time 0 and 90 min at 65 °C, activities decreased 89 % for trehalose concentration of 0.2 M. These results indicates that trehalose acts not only as inhibitor but as promoter of inactivation of PPO. The Lineweaver-Burk plot indicated that trehalose acts on PPO as a non-competitive inhibitor during the 65 °C treatment. Two mechanisms of PPO inactivation in the presence of trehalose were suggested; one is the suppression of PPO activation cause by a thermal treatment, and another is the conformational change to inactivation form of PPO in conjunction with trehalose and a thermal treatment. Additionally, apple juice including 0.2 or 0.5 M trehalose with 65 °C treatment indicated slow browning than the juice with 0.2 or 0.5 M sucrose or without sugars. This result demonstrates that the preventing of browning with trehalose is a viable industrial food process.

基于ADAMS的果园果品三级减振拖车减振性能研究

To enhance the vibration-damping performance of orchard transport trailers and reduce the damage rate during fruit transportation, this study constructed a D-level simulation pavement analyzed trailer's vibration-damping system, and optimized design of two types of three-stage vibration-damping transport trailers. The vibration mechanical properties of Fuji apples were experimentally evaluated, revealing a positive correlation between damage rate and vibratior acceleration. By utilizing vibration acceleration as a vibration-damping parameter, Adams software was employed to simulate the trailer's vibration-damping performance. The results demonstrate that the three-stage trailer with rubber vibration-damping pads in the horizontal direction exhibits superior vibration-damping effectiveness compared to existing trailers.

Effect of ultrasound treatment in fresh apple juices from different cultivars

The sonication process is based on the cavitation phenomenon, which allows the extraction of target compounds, homogenization of solutions, and breakdown of plant cells. Thus, this paper aimed to assess the effect of ultrasound treatment in fresh apple juice to control the enzymatic browning effect. Three different apple varieties, Gala, Fuji and Argentina, were used to extract the juices, and were then subjected to ultrasound treatment for 0, 5, 15, and 30 minutes. Total soluble solids, citric acid content, pH, phenolic compound concentration, and color aspects were evaluated. Argentina apple variety had higher total soluble solids and pH values, with no visual differences between treatments. In contrast, ultrasound treatment of the fuji apple had a statistical difference to the control sample, regarding citric acid content. The analysis of the L* parameter, representing luminosity, showed slight variations ranging from 24.78 to 28.27 in all samples, with no significant differences observed among different treatment durations. Furthermore, the a* parameter showed a significant difference only for the Gala apple in the 0 and 5 min treatment. The b* and Chroma value was higher in Argentina variety (5.78 to 7.05 and 6.08 to 7.42, respectively) than in Fuji and Gala. On the other hand, a statistical difference was observed in the °HUE in Gala variety, faced to Fuji and Argentina. The content of phenolic compounds in the apples’ varieties remained unaltered by ultrasound treatment, with values ranging from 52.47 to 116.23 mg of gallic acid equivalent L-1. These unexpected results indicated no significant variations between the sonification durations in the evaluated parameters. Thus, it is suggested that a new ultrasound procedure utilizing a probe and/or temperature control may be more effective in diminishing the enzymatic browning effect.

Temperature-induced metabolic changes of apples infected with Penicillium expansum characterized by non-targeted high-resolution mass spectrometry

Blue mold caused by Penicillium expansum is a prevalent postharvest disease that affects quality of apples during storage and transportation and is responsible for considerable, economic losses to the apple industry. Patulin (PAT), a secondary metabolite of P. expansum, is toxic and widely found in apples and their products, which is hazardous to human health. In this study, Fuji apples were inoculated with P. expansum then subjected to both room-temperature storage and cold storage. Measurements of the lesion diameter and PAT content revealed that the growth rate of P. expansum was lower during cold storage but the PAT content was higher, even in samples with the same lesion diameter. Non-targeted high-resolution mass spectrometry was employed to examine the metabolic changes in the infected tissues for a fixed lesion diameter (after 24 d of cold storage and 7 d of room-temperature storage). Clear differences were observed in the contents of organic acids, lipids, flavonoids, sugars, and other metabolites. Compared with the apples stored at room temperature, downregulation of metabolic pathways related to disease resistance and upregulation of those related to PAT synthesis at cold storage. The obtained results further elucidate the effects of temperature on P.expansum infection and apple resistance, thus providing a theoretical basis for the prevention and control of this problematic plant pathogen.