Characterization of Key Compounds of Organic Acids and Aroma Volatiles in Fruits of Different Actinidia argute Resources Based on High-Performance Liquid Chromatography (HPLC) and Headspace Gas Chromatography-Ion Mobility Spectrometry (HS-GC-IMS)

Effects of foliar fertilizer additives on grape fruit quality and endogenous hormones in leaves

BACKGROUND

Foliar fertilizer adjuvant is a fertilizer adjuvant that can improve the efficiency of plant leaf nutrient absorption. It is an effective means to reduce fertilizer usage and protect the environment, and plays an important role in agricultural production. However, under drought stress, traditional foliar fertilizers are susceptible to photolysis and evaporation loss, which affects the efficiency of nutrient absorption. This experiment used the 10-year-old grape 'Zitian Seedless' planted in the Wuwei area of the Hexi Corridor as the test material, focusing on foliar fertilizer adjuvants, and through its synergistic effect, explored the effects of potassium dihydrogen phosphate combined with different foliar fertilizer adjuvants on leaf endogenous hormones and fruit quality.

METHOD

This experiment had a total of six treatments: CK (potassium dihydrogen phosphate), T1 (potassium dihydrogen phosphate + ethylated and methylated vegetable oil), T2 (potassium dihydrogen phosphate + silicone), T3 (potassium dihydrogen phosphate + green citrus oil), T4 (potassium dihydrogen phosphate + sodium nitrophenolate aqueous solution), T5 (potassium dihydrogen phosphate + triacontanol solution + benzylaminopurine). The effects of different foliar fertilizer adjuvants on grape fruit quality and endogenous hormones in leaves were explored through a solar greenhouse experiment.

RESULTS

Different foliar fertilizer adjuvants can improve the quality of fresh grapes, and each treatment significantly increased the content of soluble solids in the fruit. T4 (potassium dihydrogen phosphate + sodium nitrophenolate) had the best effect: the single fruit weight, Vc, tannin and anthocyanin content of the mature fruit increased by 52.55%, 64.68%, 24.97%, and 152.56% respectively compared with CK, and the organic acid content decreased significantly. At the same time, the total content of aroma substances reached 1188.90 µg·kg⁻¹, which was 86.25% higher than that of CK. The analysis of endogenous hormones in leaves showed that T4 treatment had the most significant effect on ZT at the inflorescence separation stage, and the most significant effect on SA, IAA and ABA at the expansion stage, which were 121.89%, 15.62%, 137.23% and 37.36% higher than those of CK at the same period. In addition, T4 treatment had the lowest drug cost and was more economical.

CONCLUSION

This study revealed the effects of different foliar fertilizer adjuvants on the fruit quality and endogenous hormones of 'Zitian Seedless' grapes. It provides an efficient and low-cost foliar fertilizer adjuvant application scheme for grape cultivation in the Hexi Corridor region, which has important practical significance for improving the economic benefits and sustainable development of the fresh grape industry.

Foliar application of nano zero-valent iron improves the fruit quality of 'Yanfu No.6' apple

BACKGROUND

In recent years, the apple industry in Jingning County has developed rapidly. However, due to the neglect of the importance of trace elements in apple cultivation, iron chlorosis often occurs in fruit trees, affecting the growth of the industry. This study investigates the effects of different concentrations of nano-zero-valent iron (nZVI) on apple tree growth and fruit aims to provide theoretical references for determining the optimal nZVI concentration to improve the quality of Jingning apples.

RESULTS

This study systematically analyzed the effects of different concentrations of nanoscale zero-valent iron (nZVI) on the growth and fruit quality of 'Yanfu No.6' apple trees. The experimental results showed that compared with the control group (CK), the T2 treatment group at a concentration of 10 mg L⁻¹ significantly promoted the growth of apple tree shoots, as evidenced by an increase of about 15% in shoot length and a 10% increase in base diameter (p < 0.05). At the same time, this concentration treatment significantly improved the photosynthesis rate, SPAD value, and enzyme activities of apple leaves, including peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT), and the enhancement effect remained stable at multiple time points. Furthermore, the T2 treatment at a concentration of 10 mg L⁻¹ significantly improved the appearance quality and intrinsic quality of apple fruit, specifically by increasing fruit weight, achieving a coordinated ratio of fruit diameter, having moderate hardness, and increasing soluble protein and vitamin C content.

CONCLUSION

In this study, the appropriate concentration of nZVI promoted the growth and fruit quality of "Yanfu No.6" apple tree, among which, the nano-zero-valent iron with a concentration of 10 mg L- 1 had a significant effect on the growth and development of "Yanfu No.6" apple. This finding not only provides a theoretical basis and practical guidance for the application of nZVI in fruit tree production, but also provides a useful reference for the production of other fruit trees and crops. However, future studies are needed to further explore the regulation mechanism of nZVI on fruit tree growth and the molecular mechanism of its effect on fruit quality. Meanwhile, the environmental risk assessment and safety studies of nZVI should be strengthened to ensure its sustainable application and reduce the potential risks. These studies will provide a more comprehensive and in-depth scientific support for the widespread application of nZVI in agricultural production.

Discrimination of coal geographical origins through HS-GC-IMS assisted with machine learning algorithms in larceny case

The process of globalization and industrialization has resulted in a rise in the theft of coal and other related products, thereby becoming a focal point for forensic science. This situation has engendered an escalated demand for effective detection and monitoring technologies. The precise identification of coal trace evidence presents a challenge with current methods, owing to its minute quantity, fine texture, and intricate composition. In this study, we integrated machine learning with the identification of volatiles to accurately differentiate coal geographical origins through the application of headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS). The topographic distribution of volatiles in coals was visually depicted to elucidate the subtle distinctions through spectra and fingerprint analysis. Additionally, four supervised machine learning algorithms were developed to quantitatively predict the geographical origins of natural coals utilizing the HS-GC-IMS dataset, and these were subsequently compared with unsupervised models. Remarkable volatile compounds were identified through the quantitative analysis and optimal Random Forest model, which offered a rapid readout and achieved an average accuracy of 100 % in coal identification. Our findings indicate that the integration of HS-GC-IMS and machine learning is anticipated to enhance the efficiency and accuracy of coal geographical traceability, thereby providing a foundation for litigation and trials.

Investigation of different ingredients affected the flavor changes of Yu-Shiang shredded pork by using GC-IMS and GC-MS combined with E-nose and E-tongue

The objective of this study was to assess and compare the characteristics of Yu-Shiang Shredded Pork made with different ingredients by using physicochemical measurements and intelligent sensory analysis. The study revealed that there were 18 varied amino acids present, with the taste active values (TAVs) of Leu, Glu, Asp, Asn, and Ala all higher than 1.0. Intelligent sensory analysis showed that the samples lacking lettuce and fungus had similar aromas and flavors, while those lacking shredded pork and pickled chillies had distinct aromas and flavors. Moreover, VOCs (volatile organic compounds) were detected in five types of Yu-Shiang Shredded Pork, with 43, 42, 53, 36, and 50 identified in GC-MS (gas chromatography-mass spectrometry), respectively. Olefins (20.62 %-30.93 %) were the most abundant. GC-IMS (gas chromatography-ion mobility spectrometry) detected 68 volatiles flavor compounds, with esters having a significantly higher relative content than other compounds, indicating their significant role in the flavor formation process of Yu-Shiang Shredded Pork. Furthermore, the Orthogonal Partial Least Squares-discriminant analysis (OPLS-DA) model analysis identified 19 marker compounds that could differentiate the five types of Yu-Shiang Shredded Pork. These fundamental results lay the groundwork for future research on the connection between ingredients and the flavor characteristics of Yu-Shiang Shredded Pork.

Evaluation of Loquat Jam Quality at Different Cooking Times Based on Physicochemical Parameters, GC-IMS and Intelligent Senses

The study compared and analyzed the quality of loquat jam with different cooking times through physicochemical parameters, headspace-gas chromatography-ion migration spectroscopy (HS-GC-IMS) and intelligent senses. The results showed that with the prolongation of the cooking time, the color of loquat jam slowly deepened, the energy significantly increased, the adhesiveness, gumminess, hardness and chewiness enhanced, the free amino acid content increased from 22.40 to 65.18 mg/g. The organic acid content increased from 1.64 to 9.82 mg/g. Forty-seven volatile flavor compounds were identified in five types of loquat jam using HS-GC-IMS, among which the relative content of aldehydes was sharply higher than that of other chemical substances, playing an important role in the flavor formation of loquat jam. LJ0, LJ1 and LJ2 had higher aldehyde content, followed by LJ3 and LJ4 had the lowest aldehyde content. The orthogonal partial least squares-discriminant analysis (OPLS-DA) screened 15 marker compounds that could distinguish five types of loquat jam. The E-nose results showed a significant difference in olfactory sense between loquat jam cooked for 100 and 120 min. The E-tongue results corroborated the results of free amino acids (FAAs) and organic acids, indicating that the gustatory sense of loquat jam changed significantly when the cooking time reached 120 min. The results provided a basis for further research on the relationship between the cooking process and quality characteristics of loquat jam.

Flavor Quality Analysis of Ten Actinidia arguta Fruits Based on High-Performance Liquid Chromatography and Headspace Gas Chromatography-Ion Mobility Spectrometry

Actinidia arguta is a fruit crop with high nutritional and economic value. However, its flavor quality depends on various factors, such as variety, environment, and post-harvest handling. We analyzed the composition of total soluble sugars, titratable acids, organic acids, and flavor substances in the fruits of ten A. arguta varieties. The total soluble sugar content ranged from 4.22 g/L to 12.99 g/L, the titratable acid content ranged from 52.55 g/L to 89.9 g/L, and the sugar-acid ratio ranged from 5.39 to 14.17 at the soft ripe stage. High-performance liquid chromatography (HPLC) showed that citric, quinic, and malic acids were the main organic acids in the A. arguta fruits. Headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) detected 81 volatile compounds in 10 A. arguta varieties, including 24 esters, 17 alcohols, 23 aldehydes, 7 ketones, 5 terpenes, 2 acids, 1 Pyrazine, 1 furan, and 1 benzene. Esters and aldehydes had the highest relative content of total volatile compounds. An orthogonal partial least squares discriminant analysis (OPLS-DA) based on the odor activity value (OAV) revealed that myrcene, benzaldehyde, methyl isobutyrate, α-phellandrene, 3-methyl butanal, valeraldehyde, ethyl butyrate, acetoin, (E)-2-octenal, hexyl propanoate, terpinolene, 1-penten-3-one, and methyl butyrate were the main contributors to the differences in the aroma profiles of the fruits of different A. arguta varieties. Ten A. arguta varieties have different flavors. This study can clarify the differences between varieties and provide a reference for the evaluation of A. arguta fruit flavor, variety improvement and new variety selection.