Effects of Different Postharvest Precooling Treatments on Cold-Storage Quality of Yellow Peach (Amygdalus persica)

Multidimensional analysis of the flavor characteristics of yellow peach at different ripening stages: Chemical composition profiling and sensory evaluation

The flavor evolution of yellow peaches during ripening was investigated using a gas chromatography-mass spectrometer (GC-MS), metabolomics, and electronic sensoristic techniques. Of the 41 volatiles quantified, 13 increased the intensity of the aroma based on the odor activity values (OAVs). Additionally, 142 non-volatile compounds were identified. Metabolic pathway analysis indicated that the formation of xanthophyll esters, due to substrate competition, resulted in a reduction of carotenoid-derived volatiles. Electronic nose (E-nose) analysis revealed that the key sensor W1C-associated volatiles had a green aroma, while W1S and W2S-associated volatiles showed a fruity aroma. Electronic tongue (E-tongue) analysis revealed that L-norleucine, L-isoleucine, isoleucine, L-tyrosine, L-valine, 4-Hydroxybenzaldehyde, cinnamic acid, and rutin positively correlated with umami and sweetness. Conversely, cis-aconitic acid and (-)-epigallocatechin positively correlated with sourness or astringency. Moreover, 20 volatiles, including γ-decalactone, linalool, and (Z)-3-hexenyl acetate, were positively correlated with umami or sweetness, while 7 volatiles were positively correlated with sourness or astringency.

Inhibition Effects of Infrared Radiation Prior to Cold Storage Against Alternaria alternata on Yellow Peach (Amygdalus persica)

During postharvest storage, the yellow peach (Amygdalus persica) is susceptible to infection by Alternaria alternata, which causes fruit decay and produces multiple Alternaria toxins (ATs), leading to economic losses and potential health risks. The present study investigated the inhibitory effects of infrared radiation treatment against A. alternata on yellow peaches. Our in vitro experimental results indicated that infrared radiation at 50 °C for 30 min could completely inhibit fungal growth and AT production. Furthermore, infrared treatments prior to cold storage effectively delayed the onset of decay and significantly reduced the lesion diameter, decay rate, and AT levels in the yellow peaches inoculated with A. alternata. After the peaches underwent infrared radiation at 50 °C for 30 min and then cold storage for 60 days, the levels of tenuazonic acid, alternariol, alternariol methyl ether, and altenuene in the yellow peaches decreased by 95.1%, 98.6%, 76.1%, and 100.0%, respectively. Additionally, infrared radiation caused slight changes in their firmness, total soluble solids, and concentrations of sugar and organic acids, indicating minor negative impacts on the quality of the yellow peaches. Therefore, the present work provides a novel strategy for controlling A. alternata and AT contamination, thereby extending the shelf-life of yellow peaches, and improving food safety administration.

Early Detection of Slight Bruises in Yellow Peaches (Amygdalus persica) Using Multispectral Structured-Illumination Reflectance Imaging and an Improved Ostu Method

Assessing the internal quality of fruits is crucial in food chemistry and quality control, and bruises on peaches can affect their edible value and storage life. However, the early detection of slight bruises in yellow peaches is a major challenge, as the symptoms of slight bruises are difficult to distinguish. Herein, this study aims to develop a more simple and efficient structured-illumination reflectance imaging system (SIRI) and algorithms for the early nondestructive detection of slight bruises in yellow peaches. Pattern images of samples were acquired at spatial frequencies of 0.05, 0.10, 0.15, and 0.20 cycle mm-1 and wavelengths of 700, 750, and 800 nm using a laboratory-built multispectral structured-illumination reflectance imaging system (M-SIRI), and the direct component (DC) and alternating component (AC) images were obtained by image demodulation. A spatial frequency of 0.10 cycle mm-1 and wavelength of 700 nm were determined to be optimal for acquiring pattern images based on the analysis of the pixel intensity curve of the AC image; then, the pattern images of all yellow peaches samples were obtained. The ratio image (RT) between the AC image and the DC image significantly enhances bruise features. An improved Otsu algorithm is proposed to improve the robustness and accuracy of the Otsu algorithm against dark spot noise in AC and RT images. As a comparison, the global thresholding method and the Otsu method were also applied to the segmentation of the bruised region in all samples. The results indicate that the I-Otsu algorithm has the best segmentation performance for RT images, with an overall detection accuracy of 96%. This study demonstrates that M-SIRI technology combined with the I-Otsu algorithms has considerable potential in non-destructive detection of early bruises in yellow peaches.

Effect of Different Postharvest Pre-Cooling Treatments on Quality of Water Bamboo Shoots (Zizania latifolia) during Refrigerated Storage

Post-harvest pre-cooling of water bamboo shoots (WBS) [Zizania latifolia] can effectively delay its quality deterioration. Six types of pre-cooling treatments were used to pre-cooling post-harvest WBS, including cold slightly acidic electrolytic water pre-cooling (CSAEW), cold water pre-cooling (CWPC), vacuum pre-cooling (VPC), strong wind pre-cooling (SWPC), refrigerator pre-cooling (RPC), and fluid ice pre-cooling (FIPC). The effects of different pre-cooling treatments on the quality of refrigerated WBS were investigated. The results showed that the FIPC treatment was harmful to the storage quality of WBS, while the other five pre-cooling treatments could extend the shelf life of WBS to some extent. These pre-cooling treatments can inhibit the respiration of WBS, slow down its weight loss and lignification process, and maintain its relatively high levels of nutrient content and antioxidant activity. The CSAEW treatment outperformed other treatments in terms of bactericidal action and microbiological content control for WBS during storage. The protective effect of CSAEW treatment on the storage quality of WBS was relatively the best, and extended the shelf life of WBS by 12 days compared to the control group. This study indicated that the CSAEW pre-cooling treatment offers a new choice for pre-cooling root vegetables.

Synergistic mechanism of steam blanching and freezing conditions on the texture of frozen yellow peaches based on macroscopic and microscopic properties

Freezing and blanching are essential processing steps in the production of frozen yellow peaches, inevitably leading to texture softening of the fruit. In this study, the synergistic mechanism of stem blanching, freezing conditions (-20°C, -40°C, -80°C, and liquid nitrogen [-173°C]), and sample sizes (cubes, slices, and half peaches) on macroscopic properties of texture, cellular structure, and ice crystal size distribution of frozen yellow peaches were measured. Blanching enhanced the heat and mass transfer rates in the subsequent freezing process. For nonblanched samples, cell membrane integrity was lost at any freezing rate, causing a significant reduction in textural quality. Slow freezing further exacerbated the texture softening, while the ultra-rapid freezing caused structural rupture. For blanched samples, the half peaches softened the most. The water holding capacity and fracture stress were not significantly affected by changes in freezing rate, although the ice crystal size distribution was more susceptible to the freezing rate. Peach cubes that had undergone blanching and rapid freezing (-80°C) experienced 4% less drip loss than nonblanched samples. However, blanching softened yellow peaches more than any freezing conditions. The implementation of uniform and shorter duration blanching, along with rapid freezing, has been proven to be more effective in preserving the texture of frozen yellow peaches. Optimization of the blanching process may be more important than increasing the freezing rate to improve the textural quality of frozen yellow peaches.

Horticulture crop under pressure: Unraveling the impact of climate change on nutrition and fruit cracking

Climate change is increasingly affecting the nutritional content and structural integrity of horticultural crops, leading to challenges such as diminished fruit quality and the exacerbation of fruit cracking. This manuscript systematically explores the multifaceted impacts of these changes, with a particular focus on the nutritional quality and increased incidence of fruit cracking. An exhaustive review of current research identifies the critical role of transcription factors in mediating plant responses to climatic stressors, such as drought, temperature extremes, and saline conditions. The significance of transcription factors, including bHLH, bZIP, DOF, MDP, HD-ZIP, MYB, and ERF4, is highlighted in the development of fruit cracking, underscoring the genetic underpinnings behind stress-related phenotypic outcomes. The effectiveness of greenhouse structures in mitigating adverse climatic effects is evaluated, offering a strategic approach to sustain crop productivity amidst CO2 fluctuations and water scarcity, which are shown to influence plant physiology and lead to changes in fruit development, nutrient dynamics, and a heightened risk of cracking. Moreover, the manuscript delves into advanced breeding strategies and genetic engineering techniques, such as genome editing, to enhance crop resilience against climatic challenges. It also discusses adaptation strategies vital for sustainable horticulture, emphasizing the need to integrate novel genetic insights with controlled environment horticulture to counteract climate change's detrimental effects. The synthesis presented here underscores the urgent need for innovative breeding strategies aimed at developing resilient crop varieties that can withstand climatic uncertainty while preserving nutritional integrity.

Effects of Different Pre-Cooling Methods on the Shelf Life and Quality of Sweet Corn (Zea mays L.)

The strong wind pre-cooling (SWPC), ice water pre-cooling (IWPC), vacuum pre-cooling (VPC), natural convection pre-cooling (NCPC), and slurry ice pre-cooling (SIPC) techniques were used to pre-cool the fresh sweet corn (Zea mays L.), and then the pre-cooling treated sweet corn samples were stored at 4 °C for 28 days. During refrigeration, quality indicators, such as hardness, water loss, color, soluble solids content, and soluble sugar, were determined. In addition, oxidation indicators, such as peroxidase, catalase, ascorbic acid-peroxidase activity, and carotene content, were also measured. The results showed that the main problems of sweet corn during cold storage were water loss and respiration. The pre-cooling speed of SWPC is the fastest, and the latent heat of sweet corn can be removed in only 31 min. SWPC and IWPC could reduce the loss of fruit quality, maintain good color and hardness, inhibit the decrease of water, soluble solids, soluble sugars, and carotenoid contents, maintain balance between POD, APX, and CAT, and extend the shelf life of sweet corn. The shelf life of SWPC and IWPC corn reached 28 days, 14 days longer than SIPC and VPC treated samples, and 7 days longer than NCPC treated samples. Therefore, SWPC and IWPC are the appropriate methods to pre-cool the sweet corn before cold storage.