Next Article in Journal
Isolation and Mechanistic Characterization of Pediococcus pentosaceus WQ-30 from Kimchi for Efficient In Vitro Purine Nucleoside Degradation Relevant to Hyperuricemia
Next Article in Special Issue
Non-Destructive Prediction of NaCl Content in Pork During Ultrasound-Assisted Marination: Multiphysics Simulation and Electrical Impedance Spectroscopy
Previous Article in Journal
One-Pot Enzymatic Bioconversion of Native Whey for the Simultaneous Production of Galacto-Oligosaccharides and Antioxidant Peptides
Previous Article in Special Issue
Achieving Lasting Umbilical Cord Decontamination and Sustainable Stem Cell Sourcing by Combining Plasma-Functionalized Liquid and Ultrasound
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Foods
Volume 15
Issue 5
10.3390/foods15050815
foods-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Evaluating the Effects of Electron Beam Irradiation on Coffee Beans and Their Storage Quality

by
Chengpiao Tian
1,2,
Yuan Zhao
1,
Qiulan Huang
1,
Guanru Huang
1,
Shuaimin Liu
1,
Qingjing Cen
1,
Debao Niu
3 and
Er-Fang Ren
1,2,4,*
1
Guangxi Subtropical Crops Research Institute, Nanning 530001, China
2
Guangxi Subtropical Fruit Processing Technology Innovation Center, Nanning 530001, China
3
College of Light Industry and Food Engineering, Guangxi University, Nanning 530004, China
4
Key Laboratory of Quality and Safety Control for Subtropical Fruit and Vegetable, Ministry of Agriculture and Rural Affairs, Nanning 530001, China
*
Author to whom correspondence should be addressed.
Foods 2026, 15(5), 815; https://doi.org/10.3390/foods15050815
Submission received: 31 December 2025 / Revised: 6 February 2026 / Accepted: 17 February 2026 / Published: 27 February 2026
(This article belongs to the Special Issue Non-Thermal Processing Technologies for Sustainable Food Processing)
Browse Figures
Versions Notes

Abstract

This study focuses on the storage process of coffee beans, employing electron beam irradiation (EBI) to investigate the comprehensive effects of different irradiation doses on coffee beans and their storage process, including physicochemical indicators, microbial abundance, and flavor compounds. The results showed that a 2 kGy dose of EBI could effectively reduce the total number of bacteria, molds, and yeasts in green coffee beans (GCBs), while a dose of 4 kGy can completely inactivate the bacteria and maintain this effect for one month. Compared with the control sample that has not undergone processing by EBI (CK), the crude fat content of the irradiated samples decreased, accompanied by a significant increase in acid value. After 30 days of storage, compared with the CK-30 sample, EBI treatment significantly reduced both the moisture content and overall brightness value of GCB. The analysis of aroma compounds in roasted coffee beans (RCBs) revealed that substances related to Maillard reaction, caramelization reaction and sugar degradation, such as 2-Furanmethanol and acetic acid, changed in the irradiated samples, but had no significant effect on the characteristic components like caffeine and the aroma detected by the electronic nose. The obtained results provide a scientific basis for applying irradiation technology to the preservation of coffee beans.

1. Introduction

Coffee, a plant belonging to the genus Coffea in the family Rubiaceae, is an important economic crop in tropical developing countries, and one of the most highly traded agricultural commodities and popular beverages in the world [1,2]. The statistics predict that world coffee production for 2024/25 is forecast to be 6.9 million bags higher than the previous year, at 174.9 million. The rapid growth in coffee demand in such a populous country as China has significantly contributed to the increase in global coffee consumption. For instance, the International Coffee Organization pointed out that China’s demand for coffee in 2024 will be 378,000 tons [3]. In the major coffee-producing regions, there are usually one or two main harvest seasons each year, and the harvesting period can last for 4 to 6 months. This indicates that there will be a 6–8 month harvest gap each year, during which time the stored coffee needs to be used [4]. The core of coffee storage lies in controlling the environment to keep the chemical and physical state of coffee beans stable, especially to delay the oxidation and volatilization of flavor substances, so as to ensure that the coffee does not deteriorate in quality before reaching the consumers [5].
After preliminary processing, such as sun-drying or water-washing, the volatile aroma, flavor, cleanliness (free from musty smell and excessive fermentation smell), soluble substances, and easily oxidizable oils (which are closely related to freshness) are the core indicators for evaluating the quality of coffee beans [6,7,8]. Pest infestation, mold growth, and external color serve as relatively intuitive external quality indicators [5,9]. In the coffee industry chain, fresh coffee cherries are typically stored and transported as green beans after harvesting and initial processing. However, the quality of green coffee beans (GCBs) is highly susceptible to deterioration due to improper storage, such as acidification caused by lipid oxidation, color change caused by non-enzymatic browning, and spoilage caused by the microbial growth [10,11]. Therefore, how to effectively inhibit microbial activities and delay lipid oxidation during long-term storage has become a key challenge in safeguarding the commercial value and food safety of coffee. When coffee beans are stored in their roasted state, the freshness of the coffee is studied from the perspectives of chemical composition, taste and aroma [12,13].
Currently, the common method for extending the shelf life of coffee beans is freezing. However, there is some controversy regarding the impact of freezing on the flavor quality of coffee. Some people believe that coffee beans with extended shelf life are merely in a “pseudo-fresh” state, and the flavor of the brewed coffee is not ideal [14]. Opting for non-thermal and chemical-free alternative technologies to extend the shelf life of plant-based products represents a positive development trend. Electron beam irradiation (EBI) is an emerging irradiation technology that has been accelerated to possess extremely high energy and can exert insecticidal and sterilizing effects, offering a non-thermal preservation technique that effectively extends shelf life while minimizing nutrient loss [15,16]. Compared with other irradiation methods, EBI technology has shorter processing time, no attenuation of radiation sources and safety performance [17,18], and is more in line with the actual needs of oxidation in the storage of Chinese medicinal materials and food. In 1980, the Food and Agriculture Organization of the United Nations (FAO), International Atomic Energy Agency (IAEA) and World Health Organization (WHO) issued a statement that food irradiation at doses of 10 kGy or less is safe from a microbiological and nutritional perspective; over 55 countries worldwide have authorized the application of irradiation in food processing [19,20,21]. At present, nine categories of irradiated food hygiene standards and 17 standards for the processing technology of irradiated foods, including fresh fruits and vegetables, dried fruits and preserves, pollen, and spices, have been approved in China [19]. Regarding the impact of EBI treatment on chemical composition, there have been comparative studies on the use of EBI instead of high-temperature sterilization to prevent the attenuation of characteristic components. A 4–6 kGy dose of EBI can reduce unpleasant sulfur odors, enhance sweetness and aroma, significantly improve the sensory quality of broccoli sprout juice [14], and also reduce the content of tea polyphenols and caffeine in brewed tea, increase the content of soluble sugars [22], accelerate the aging of baijiu (a Chinese liquor) [23], but its potential impact on lipid oxidation has not yet been studied or reported. Preliminary studies demonstrated that a 5–10 kGy dose of EBI could effectively reduce the microbial count by 2–4 orders of magnitude of GCBs, without causing excessive impact on the basic rheology and spectral properties of coffee [24]. These studies provide preliminary scientific evidence for the application of EBI in post-harvest storage of GCB. However, further exploration is still needed to understand the impact of EBI on the key chemical components and overall quality of coffee, which is a flavor-sensitive product.
This study aims to investigate the effects of EBI on the physicochemical indicators of coffee, including color, moisture, lipid oxidation, microbial count, characteristic components, and aroma components, in order to clarify the impact of this irradiation treatment on coffee and preliminarily evaluate its applicability to coffee beans.

2. Materials and Methods

2.1. Materials and Reagents

The Arabica green coffee beans (GCBs) were harvested from the plantation of Dongxing Shima Co., Ltd., located in Dongxing County, Fangchenggang City, Guangxi Zhuang Autonomous Region (altitude = 200 m), China. The harvested GCBs were processed through washing, then sun-dried and stored sealed at a constant temperature. The roasted coffee beans (RCBs) were produced by roasting machine (ACR002A-050, Mita Life Electrical Appliances Co., Ltd., Foshan, China). To roast the GCBs, they were carefully roasted at 200 °C for 7–8 min to achieve a medium roast (Agtron value 55–60). Chlorogenic acid (CGA), caffeine, and trigonelline standards were purchased from Desite Biotechnology Co., Ltd. (Chengdu, China); phosphoric acid, methanol, acetonitrile (all of chromatographic grade), Thermo Fisher Scientific Inc. (Shanghai, China); isopropanol, petroleum ether, acetic acid are all analytical grade.

2.2. EBI and ALST Treatment of Coffee Beans

Both GCBs and RCBs were spread in sealed bags at a thickness of less than 1 cm during irradiation. The experiment was conducted using an EBI facility (accelerating voltage: 10 MeV) at a constant average power of 22.4 kW. Based on the principle that the cumulative dose of food does not exceed 10 kGy [21], five target absorbed dose groups were established: 2, 4, 6, 8, and 10 kGy. To maintain constant power, a pulse repetition frequency of 200 Hz was used for the 2 kGy group, while a frequency of 381 Hz was applied for the higher-dose groups. The exposure time of the samples under the beam was controlled to achieve the precise preset dose for each group (the dose was calibrated using a potassium dichromate (silver) liquid chemical dosimeter) [14,25]. The entire irradiation process was carried out sequentially in ascending order of dose and completed within 50 min. Irradiated GCBs were stored at 50 °C and 50% RH in a constant temperature and humidity incubator (Hunan Hexi Instrument Equipment Co., Ltd., Changsha, China) under accelerated conditions, and samples were taken for testing at regular intervals within 30 days. The RCBs were placed in a constant temperature and humidity incubator at 37 °C and 50% RH, and tested within 7 days. CK represents the control sample that has not undergone processing by EBI. CK-0 was equivalent to a 0 kGy treatment and 0 day accelerated storage of the samples. CK-30 was equivalent to a 0 kGy treatment and 30 days accelerated storage of the samples.

2.3. Testing Methods for GCBs

2.3.1. Color Measurement of GCBs

GCB samples were collected at 0, 7 and 30 days. Color parameters (L*, a*, b*) were measured using a CR-400 colorimeter (Konica Minolta, Inc., Osaka, Japan). Each group conducted 5 repetitions of the measurement, and the average values were calculated after excluding the maximum and minimum values.

2.3.2. Moisture Determination of GCBs

GCB samples were sampled at 0, 7 and 30 days. The moisture content was determined using a SN-SH moisture analyzer (Shangyi Instrument Equipment Co., Ltd, Shanghai, China). A 2 g of sample was heated at 120 °C until a constant weight was achieved, and the moisture content was recorded.

2.3.3. Microbiology Experiments of GCBs

GCB samples were taken every 7 days for microbiology experiments. Total bacterial counts were assessed in accordance with the GB 4789.2-2022 standard of China [26]. Yeast and mold counts were assessed in accordance with the GB 4789.15-2016 standard of China [27].

2.3.4. Determination of Lipid Oxidation Parameters

GCB samples were sampled at 0 and 30 days. Acid value (AV) was assessed in accordance with the GB 5009.229-2016 standard of China [28]. Peroxide value (POV) was assessed in accordance with the GB 5009.227-2023 standard of China [29].

2.4. Determination of the Characteristic Components of Coffee Beans

Coffee bean CGA, caffeine, and trigonelline content were analyzed according to the method of Getachew et al., with slight modifications [30]. The method detection limits (LDLs) were 0.70 mg/kg for CGA, 0.50 mg/kg for caffeine, and 0.50 mg/kg for trigonelline. The method quantification limits (LOQs) were 2.00 mg/kg for CGA, 1.50 mg/kg for caffeine, and 1.50 mg/kg for trigonelline. Standard curves were constructed using CGA, caffeine, and trigonelline standards and the results were expressed as the % dry basis (%, d.b.) concentration [30,31].
For the GCB sample, 80 mL of 0.1% phosphoric acid aqueous solution was added to 0.5 g of powder, and then it was incubated in a boiling water bath for 30 min. Then the volume was adjusted to 100 mL and filtered through a 0.22 μm polytetrafluoroethylene (PTFE) membrane [30]. For the RCB samples, the preparation followed the Specialty Coffee Association (SCA) Coffee Cupping Protocols; 100 mL of 94 °C water was added to 5.5 g RCB powder and was left to soak for 4 min. The supernatant was diluted 10 times and filtered through a 0.45 μm membrane [31,32].
The analysis was conducted using a Waters Alliance e2695 high-performance liquid chromatograph (Waters Co., Shanghai, China), equipped with an Athena C18 column (250 mm × 4.6 mm, 5 µm i.d) (Welch Materials, Inc., Shanghai, China); the mobile phase was composed of 0.1% phosphoric acid aqueous solution and acetonitrile in a ratio of 4:1 (v/v), with isocratic elution. The column temperature was 30 °C, the flow rate was 1.0 mL/min, and the detection wavelengths were 254 nm (for trigonelline and caffeine) and 320 nm (for CGA), with an injection volume of 10 μL.

2.5. Method for Measuring RCBs

2.5.1. Measurement of pH and Extraction Rate of RCBs

A total of 100 mL of 94 °C water was added to 5.5 g RCB powder and brewed within 2.5 min to obtain the coffee liquid. The pH value of the brewed coffee was measured using a PHS-3C pH meter (INESA Scientific Instrument Co., Ltd., Shanghai, China). The concentration of the coffee (Total Dissolved Solids, TDSs) was determined using a coffee concentration meter (ATAGO Scientific Instruments Co., Ltd., Guangzhou, China). The extraction yield is calculated according to the following formula:
Extraction Yield = TDS (%) × Extraction Liquid Weight (g)/Coffee Powder Mass (g)

2.5.2. Determination of the Aroma of RCBs by Electronic Nose

A total of 2 g RCB powder was placed into a 20 mL enrichment bottle and the enrichment treatment was conducted at room temperature for 50 min before detection. The German PEN3 electronic nose (Airsense Company, Schwerin, Germany) was set with the following parameters: Sample detection injection interval was 1 s, the cleaning time was 60 s, the zero-point calibration time was 1 s, the pre-injection time was 5 s, the test time was 110 s, and the injection flow rate was 400 mL/min. The signal stabilized after 80 s of detection. The signals from 85 to 87 s were selected for data processing and analysis [33].

2.5.3. Determination of Aromatic Compounds in RCBs

The headspace solid-phase microextraction was placed with 2 g of powder in a 20 mL headspace bottle. The 50/30 μm CAR/PDMS/DVB extraction head was inserted into the headspace part of the sample bottle. It was left to adsorb for 30 min at 60 °C. After removing the extraction head, it was inserted into the gas chromatography injection port. It was left to desorb for 3 min at 250 °C. The instrument was started, allowing us to collect data.
GC-MS analysis used the Pegasus BT gas chromatography high-throughput time-of-flight mass spectrometry analyze (Leco Co., San Jose, CA, USA). The chromatographic column was HP-5MS (30 m × 0.25 mm × 0.25 µm), and the carrier gas was high-purity helium (99.999%) at a constant flow rate of 1 mL/min. The column temperature was programmed as follows: The temperature program was at an initial temperature 30 °C, held for 3 min, increased to 90 °C at 2 °C/min, held for 3 min, increased to 230 °C at 10 °C/min, and held for 30 min. The injection port temperature was 220 °C, interface temperature was 280 °C, ion source temperature was 230 °C, EI electron energy was 70 eV, and scan mass range was m/z 35–550 [11,34].
After analyzing the samples with GC-MS, a total ion chromatogram was obtained. The NIST standard spectrum library was used to search and verify the relevant parameters such as the literature, retention time, mass spectrum, and retention index to qualitatively identify the main compounds. The peak area normalization method was used to quantitatively determine the relative content of the detected compounds.

2.6. Statistical Analysis

Except for the color determination, which was repeated 5 times, all other experiments were performed in triplicate to ensure reproducibility, and all graphs and data presentations show mean values with corresponding standard deviations. One-way analysis of variance (ANOVA) was performed using IBM SPSS Statistics 26 (29 Inc., Chicago, IL, USA), and Duncan’s test was applied to compare means at the 5% significance level, with statistical significance defined as p < 0.05. Graphing was conducted using Origin 2023 software (OriginLab Corp., Northampton, MA, USA). The experimental data of volatile compounds in RCBs was performed using the Metware Cloud, a free online platform for data analysis (https://cloud.metware.cn, accessed on 21 November 2025).

3. Results and Discussion

3.1. Color Intensity and Moisture of GCBs

As shown in Table 1, under accelerated storage at 50 °C, the moisture content and color of the irradiated coffee beans changed. The L* (lightness) values and ΔE (color difference) did not show significant differences among the samples of different irradiation doses (p > 0.05). Compared with CK-0 (0 kGy, 0 d), the L* values of the irradiated samples at the initial storage stage did not decrease significantly. It was observed that irradiation treatments below 10 kGy did not yet immediately cause any color changes [35]. The L* value was slightly increased at 30 days, and the greatest change was from 53.13 to 56.9 (CK) (p < 0.05). In Gallego’s study [9], coffee beans packaged with various materials showed an increase in L* value after a certain storage time. And the ΔE values at 30 days were 1.75 to 3.33, all higher than the ΔE values of the same dose treatment at 7 days, indicating that ALST pretreatment may have accelerated the surface of GCB browning process. The a* (red–green axis) values of 6–10 kGy high-dose samples were more pronounced at 30 days. The a* value of 8 kGy was 4.11, significantly higher than the a* value of 3.28 in the CK-30. With the increase in storage days, the a* and b* (yellow–blue axis) values of each dose sample increased, indicating an increase in the redness and yellowness of the coffee beans. The color changes in coffee beans during storage indicate the oxidation process and biochemical degradation phenomena. Luo also found the same results in their research; during storage, there was a gradual intensification of brown rice color [36]. There was no significant difference in moisture content among samples with different EBI doses, which was similar to the research results of EBI on brown rice. The study showed that low-dose EBI treatment had a negligible effect on the change in moisture content [37]. When high-energy EBI penetrates soft-textured meat food, it transfers energy to the food, causing the food’s temperature to rise and leading to water evaporation [38]. However, coffee beans and brown rice are hard in texture and have low moisture content, which prevents this phenomenon from occurring. The moisture content decreased from the initial 6.16–6.5% to 5.52–6.04% at 7 days of storage, and further decreased to 5.08–5.56% at 30 days. After a few days of storage, regardless of whether the samples had been irradiated or not, their moisture content exhibited a decreasing trend [37,39], which might be due to respiration or storage temperature [40].

3.2. The Colony Count of GCBs

Direct action of radiation on biological macromolecules can cause structural changes or lead to oxidative apoptosis of biological macromolecules, both of which can achieve microbial elimination effects [41]. The energy level of EBI can cause differences in sterilization effects [22,42]. The total colony count of GCBs that were treated with various doses of EBI during storage is presented in Table 2; compared to unirradiated GCBs (CK group), the total number of bacterial colonies, the number of molds and yeasts were decreased significantly, and this decrease gradually increased with the increase in irradiation dose. At 0 d, the bacterial colonies of the CK-0 sample were 6.4 × 104 CFU/g, molds and yeasts were 1.9 × 105 CFU/g, and we still detected bacterial colonies of 3.7 × 103 CFU/g and molds and yeasts 2.5 × 103 CFU/g at 30 days of 37 °C storage (CK-30). The results indicate that, due to the low moisture content of GCBs and the limited nutrient supply on the surface, the microbial numbers showed a downward trend after storage for a certain period of time. The sample irradiated with a 2 kGy dose showed bacterial colonies of 5.5 × 103 CFU/g and molds and yeasts 8.6 × 103 CFU/g at 0 d. No bacterial colonies were detected, while molds and yeasts were 100 CFU/g after 7 days. The sample irradiated with a 4 kGy dose had no bacterial colonies detected after 7 days, indicating that EBI can effectively inhibit microbial contamination in GCBs and will not cause microbial resuscitation when stored under sealed conditions. This indicates that the free radicals generated by the EBI at 2 a kGy dose or higher inactivates spoilage-causing microorganisms at low temperatures.

3.3. Accelerated Lipid Oxidation of GCBs

Coffee beans have a high lipid content, and studies have shown that the lipid indicators of GCBs after EBI treatment have changed to varying degrees. As shown in Table 3, compared with the untreated samples CK-30, the crude fat content of the irradiated samples decreased to a certain extent, and there were no significant differences within the dose range of 2–10 kGy (9.47–10.07%) (p > 0.05). Additionally, the AV of the irradiated samples range from 2.12 to 2.6 mg/g, which were significantly higher than that of the CK-0 and CK-30 samples. This indicates that EBI causes fat degradation and an increase in AV in GCBs. Previous studies have generally shown that coffee lipids undergo thermal hydrolysis into free fatty acids, which are then further oxidized to form acids, manifested as an increase in AV [10]. In this study, the effect of EBI seems to be involved in interfering with the process of converting fat into fatty acids. The results of Pan et al. also found that, in rice treated with EBI, as the irradiation dose increased, the fat content of the rice decreased while the fatty acid content slowly increased [43]. However, the AV of coffee beans remained below the standard limit of 3.00 mg/g set for nuts and baked foods. The crude fat content, AV and POV of the CK-30 samples treated by ALST were all slightly higher than those of CK-0. The POV of 4 and 6 kGy samples were significantly higher than those of other dose treatments. This indicates that the increase in the POV of GCBs is influenced by both EBI and ALST. In Congsha’s research, the AV, iodine value, POV and total oxidation value of GCBs all increased with the increase in storage time, while the moisture content decreased, indicating that lipid oxidation occurred during the ALST [44].

3.4. Content of Main Characteristic Components in Coffee

The content of characteristic components in coffee beans after different EBI doses is shown as Figure 1. The caffeine content in GCBs and RCBs ranges from 1.3 to 1.37% and 1.39 to 1.56%, respectively. The trigonelline content ranges from 0.94 to 1.02% and 0.95 to 1.07%, respectively. The CGA content ranges from 3.9 to 4.33% and 1.09 to 1.42%, respectively. There is little difference in the content of characteristic components among samples treated with different EBI doses, indicating that irradiation at doses of 2 to 10 kGy will not affect the characteristic components of coffee. According to the technical guidelines for food irradiation sterilization, the overall average irradiation dose does not exceed 10 kGy [21]. This study confirms that the characteristic components of coffee beans remain stable under this irradiation dose. This is similar to the results of Wang Xue et al.’s study, where the irradiation had no significant effect on coffee acid and CGA, and the study of Xiao, where irradiation had no significant effect on the total polyphenols and caffeine content of Pu’er tea [18,45]. The direct effects of high-energy EBI and the free radicals it induces may alter the internal components of samples, thereby causing changes in effective components [46]. Khattak demonstrated that, at irradiation doses of 12 kGy or higher, the content of phenolic substances decreased [47]. Additionally, during the coffee roasting process, chlorogenic acid is subject to heat degradation, resulting in bitter phenolic compounds [48]. As a result, the ratio of CGA to caffeine/trigonelline was significantly higher in GCBs than in RCBs.

3.5. Effects of EBI on the Extraction Yield and pH of RCBs

As shown in Figure 2, the pH of the irradiated RCBs were all around 5, and no significant differences were observed among the EBI samples. Based on the pH research results, it can be inferred that the substances providing hydrogen ions in the solution were not significantly affected by EBI. The extraction rate was calculated by TDS, which was 14.05–15.16% for EBI samples, close to the extraction rate of the samples without irradiation treatment (14.65% ± 0.325). The extraction rate of 4 kGy RCBs was the highest, 15.16% ± 0.248. After the irradiation dose increased to 6 kGy, the extraction rate slightly decreased. The overall difference in the effect of different doses on the extraction rate is not significant. This is consistent with the conclusion of Zhang’s study, which stated that the two irradiation methods have no obvious influence on the water extraction of broken black tea [22]. When the irradiation dose is ≥10 kGy, sufficient energy is required to cause the degradation of macromolecular substances, resulting in the formation of hydrophilic substances (free amino acids or organic acids), thereby increasing the content of water-soluble leachable substances [41]. The radiation dose set in this study did not reach the energy level capable of causing this phenomenon, so the content of the released substances remained stable.

3.6. Effects of EBI on Aroma and Aromatic Compounds of RCBs

Figure 3 shows the radar chart of the responses of 10 sensors of the electronic nose to RCBs. The sensors with larger response intensities were W1W (sensitive to inorganic sulfides and terpenoid substances), W2W (sensitive to organic sulfides, aromatic components, and terpenoid substances), and W5S (sensitive to nitrogen oxides), indicating high contents of terpenoids and aromatic substances and intense aroma. As shown in Figure 3 and Table 4, the response values of different irradiation treatments were similar, suggesting that the EBI did not affect the aroma of RCBs. However, the effects of multiple irradiation treatments on the aroma of liquor by Jia and Zheng [49,50] were not observed at the initial stage of storage. After irradiation treatment and storage for a certain number of days, differences would be formed due to accelerated aging. The aroma of RCBs being affected slightly in this study may be related to the low moisture content or short storage time.
As shown in Figure 4, a total of 37 abundant volatile organic compounds (VOCs) were detected in all samples, and the clustering heat map analysis is shown as Figure 4A. The roasting processes yield a variety of aroma-characteristic compounds, including alcohols, ketones, aldehydes, esters, pyrazines, pyrroles, pyridines, furans, and phenols [51]. Most of these VOCs were related compounds generated during the food processing process, such as Maillard reaction, caramelization reaction, and fatty acid degradation. Figure 4B reveals the histogram of the percentage content of VOC types in coffee with different EBI doses analyzed by HS-SPME-GC-MS. Among these, the peak areas of furans accounted for more than 20% of the main VOCs in all samples. The results indicate that, in the coffee sample group, the content of Furans was the highest percentage, followed by acids. From both quantitative and qualitative perspectives, furan and pyrazine compounds are both regarded as the most important components influencing the flavor of coffee [52,53].
The seven sugar degradation compounds (18.92% of the total compounds) were also identified as the most predominant compounds in all the coffee samples. CK, 2, and 10 kGy dose samples had a significantly higher relative content of furan-based compounds than the 4, 6, and 8 kGy dose samples. This difference was mainly affected by 2-Furanmethanol (Figure 4C), its content being higher than that of other samples in both CK and 2 kGy samples. 2-Furanmethanol is the characteristic component with the highest relative content among all the detected compounds, with a special odor similar to caramel or bitter-sweet, naturally existing in certain fermented foods. Lipids have floral and fruity aromas and provide an important role in the aroma of coffee [54]. The seven fatty acid degradation and short-chain carboxylic acid derivatives (18.92% of the total compounds) in the 4, 6, and 8 kGy dose samples were slightly higher than in the CK, 2, and 10 kGy dose samples. This was mainly caused by acetic acid, the most abundant fatty acid degradation compound. These aroma compounds, related to fatty acid degradation, show trends consistent with lipid oxidation indicators (acid and peroxide values). This confirms that irradiation promotes fatty acid degradation into aromas, with the dose affecting reaction rates [47]. The nitrogen-containing heterocyclic compounds are related to the Maillard reaction, which in the 4, 6, and 8 kGy dose samples were lower than that in CK, 2, and 10 kGy doses samples. These compounds are mainly generated by the caramelization reaction or the initial stage of Maillard reaction of sugar and are the core of roasting and caramel flavor. These differences in the compounds were summarized based on the high-sensitivity detection of GC-MS and were not reflected in the electronic nose detection. This might be related to the relatively weak ability of the electronic nose sensor to detect changes in trace components. Phenol compounds had a higher content than the 4, 6, and 8 kGy dose samples, mainly affected by the difference in caffeine, which is the characteristics compound of coffee. The EBI treatment does not cause the coffee to produce any new volatile organic compounds.

4. Conclusions

This study focuses on coffee beans treated with EBI, aiming to explore the comprehensive effects of different irradiation doses on the coffee beans and their storage process. The results will provide a reference for the application of EBI to coffee beans, or the development of new coffee bean storage technologies. EBI mainly affected the microbial quantity, lipid oxidation, and some aromatic compounds of coffee. At 2 kGy doses or higher, EBI can inactivate microorganisms under low-temperature conditions, significantly reducing the microbial detection levels to even none. This is of significant importance for preventing microbial-induced spoilage and ensuring food safety. EBI treatment simultaneously affects the content of both fats and fatty acids, manifesting as an increase or decrease in their levels. This phenomenon may be attributed to an acceleration effect on oxidation-reduction reactions induced by EBI [55,56]. The trends of some aromatic compounds related to Maillard reaction, caramelization reaction and sugar degradation in irradiated samples and CK were consistent with the changes in fat content and fatty acid value in lipid determination. However, these changed compounds may not yet have reached a concentration level sufficient to alter the overall odor, and thus there is no difference in the electronic nose’s aroma. Compared with the CK, different doses of EBI had no significant effect on the characteristic components, caffeine, chlorogenic acid, and trigonelline, which is speculated to be related to the stability of the chemical properties of these characteristic components and the changes in the content of aromatic compounds. From the perspective of the storage process, the EBI treatment and a 30-day storage period will lead to a decrease in both the moisture content and the overall brightness value of coffee, and it also makes the coffee turn reddish-yellow. The above discussion, based on fundamental physicochemical data, represents a preliminary investigation into the effects of EBI treatment on coffee beans, while the underlying mechanisms have not yet been deeply explored. In summary, below the recommended irradiation processing dose of <10 kGy, especially at 2 kGy, irradiation can effectively reduce the microbial quantity in GCBs, and retain the roasting and caramel flavor substances of RCBs. However, from the perspective of GCB color and lipid oxidation, EBI’s effects, while not initially apparent, became observable after 30 days of accelerated storage. This suggests that EBI forcibly accelerated the metabolic state of the GCBs. Based on the findings of this study, further mechanistic research is required to clarify the specific pathways through which EBI influences coffee beans, thereby providing a solid theoretical foundation for its application.

Author Contributions

C.T.: Methodology, Conceptualization, Writing—original draft, Investigation, Data curation. Y.Z.: Investigation, Formal analysis. Q.H.: Investigation, Resources. G.H.: Methodology, Software, Formal analysis. S.L.: Visualization, Resources. Q.C.: Visualization, Investigation. D.N.: Methodology, Supervision. E.-F.R.: Writing—review and editing, Project administration, Investigation, Funding acquisition. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the Special Fund for Construction of Guangxi Innovation Team in National Modern Agricultural Industry Technology System (nycytxgxcxtd-2024-17-05) and the Guangxi Academy of Agricultural Sciences Basic Research Business Project (GNK 2025YP129).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Poole, R.; Kennedy, O.J.; Roderick, P.; Fallowfield, J.A.; Hayes, P.C.; Parkes, J. Coffee consumption and health: Umbrella review of meta-analyses of multiple health outcomes. BMJ 2017, 359, 5024. [Google Scholar] [CrossRef] [PubMed]
  2. de Sousa, K.; van Zonneveld, M.; Holmgren, M.; Kindt, R. The future of coffee and cocoa agroforestry in a warmer Mesoamerica. Sci. Rep. 2019, 9, 8828. [Google Scholar] [CrossRef] [PubMed]
  3. Tang, L.Y.; Shao, J.S.; Naranjo, B.M.; Zhu, Y.N.; Lieleg, O.; Song, J. Sugar or milk: Tribological study on the sensation of coffee beverages. J. Food Eng. 2024, 367, 11876. [Google Scholar] [CrossRef]
  4. Wintgens, J.N. (Ed.) Coffee: Growing, Processing, Sustainable Production: A Guidebook for Growers, Processors, Traders, and Researchers, 2nd ed.; Wiley-VCH Verlag GmbH & Co. KGaA: Weinheim, Germany, 2009; ISBN 978-3-527-32286-2. [Google Scholar] [CrossRef]
  5. Fernandez-Rosillo, F.; Quiñones-Huatangari, L.; Cabrejos-Barrios, E.M.; Abarca López, M.; Córdova Flores, Y.L.; Chavez, S.G. Estimation of the shelf life of specialty coffee in different types of packaging through accelerated testing. Beverages 2025, 11, 154. [Google Scholar] [CrossRef]
  6. Cui, D.D.; Liu, Y.; Chen, Y.P.; Feng, X.; Lu, Y.; Yu, B. Application of SPME-GC-TOFMS, E-nose, and sensory evaluation to investigate the flavor characteristics of Chinese Yunnan coffee at three different conditions (beans, ground powder, and brewed coffee). Flavour Fragr. J. 2020, 35, 541–560. [Google Scholar] [CrossRef]
  7. Amalia, F.; Aditiawati, P.; Yusianto; Putri, S.P.; Fukusaki, E. Gas chromatography/mass spectrometry-based metabolite profiling of coffee beans obtained from different altitudes and origins with various postharvest processing. Metabolomics 2021, 17, 69. [Google Scholar] [CrossRef]
  8. Chen, X.M.; Wu, P.P.; Wang, S.W.; Sun, J.; Chen, H.T. Identification of key aroma-active compounds in commercial coffee using GC-O/AEDA and OAV analysis. Foods 2025, 14, 3192. [Google Scholar] [CrossRef]
  9. Gallego, C.P.; Pabón, J.; Medina, R.D.; Osorio, V. Maintenance of the quality of coffee (Coffea arabica L.) in different packaging and storage locations. Int. J. Food Sci. 2025, 1, 5049217. [Google Scholar] [CrossRef]
  10. Wang, X. Study on the Regular of Flavor Quality of Roasted Coffee Beans During Storage Based on Accelerated Induction. Master’s Thesis, Nanjing Normal University, Nanjing, China, 2019. [Google Scholar]
  11. Cong, S.; Dong, W.J.; Zhao, J.P.; Chi, X.X.; Chen, Z.H.; Jiang, H.Q.; Shan, Y.H. Using HS-SPME-GC/MS and electronic nose technology to analyze the variation patterns of volatile components in green coffee beans during the accelerated storage period. Mod. Food Sci. Technol. 2020, 36, 250–262. [Google Scholar] [CrossRef]
  12. Smrke, S.; Adam, J.; Mühlemann, S.; Lantz, I.; Yeretzian, C. Effects of different coffee storage methods on coffee freshness after opening of packages. Food Packag. Shelf Life 2022, 33, 100893. [Google Scholar] [CrossRef]
  13. Benković, M.; Tušek, A.J. Regression Models for Description of Roasted Ground Coffee Powder Color Change during Secondary Shelf-Life as Related to Storage Conditions and Packaging Material. Beverages 2018, 4, 16. [Google Scholar] [CrossRef]
  14. Zhou, Y.; Can, L.J.; He, Z.J.; Zhao, L.F.; Li, X.W.; Xie, J.C.; Tan, C. Effect of ultra-low temperature on the non-volatile flavor quality and ultrastructure of coffee beans. J. Food Sci. Tech. 2025, 43, 89–101. [Google Scholar] [CrossRef]
  15. Yan, J.Y.; Li, Y.Y.; He, H.J.; Liu, G.M.; Tang, X.W.; Wang, Y.Q.; Peng, X.Y. Effects of electron beam irradiation on the sensory qualities and bioactive compounds of broccoli sprout juice. Food Res. Int. 2025, 199, 115365. [Google Scholar] [CrossRef] [PubMed]
  16. de Oliveiraa, P.S.; de Souza Coelho, C.C.; Campos, R.D.S.; Freitas-Silvac, O.; Júniorc, M.F. Effects of electron-beam (E-beam) irradiation on the postharvest quality of ‘golden’ papayas. Food Physics 2025, 2, 100054. [Google Scholar] [CrossRef]
  17. Wahyono, T.; Ujilestari, T.; Sholikin, M.M.; Muhlisin, M.; Cahyadi, M.; Volkandari, S.D.; Triyannanto, E. Quality of pork after electron-beam irradiation: A meta-analysis study. Vet. World 2024, 17, 59–71. [Google Scholar] [CrossRef]
  18. Nam, H.A.; Ramakrishnan, S.R.; Kwon, J.H. Effects of electron-beam irradiation on the quality characteristics of mandarin oranges (Citrus unshiu (Swingle) Marcov) during storage. Food Chem. 2019, 286, 338–345. [Google Scholar] [CrossRef]
  19. Wang, X.; Pan, Z.P.; Li, W.G.; Su, Z.P.; Chen, J.X.; He, S.; Fu, F.H. Study on aging quality of ponkan peels irradiated by 60Co-γ rays. Food Sci. 2024, 45, 205–212. [Google Scholar] [CrossRef]
  20. Hou, D.H.; Wang, C.L.; Yu, J.T.; Bai, J.Q.; Xu, H.D.; Kou, L.P. Effects of electron beam irradiation on the postharvest quality characteristics of winter jujube (Zizyphus jujuba mill. cv. Dalidongzao). J. Future Foods 2025, 2, 153–161. [Google Scholar] [CrossRef]
  21. GB 18524-2016; Chinese National Standard. National Food Safety Standard-Food Irradiation Processing Hygiene Specifications. National Food and Drug Administration: Beijing, China, 2016.
  22. Zhang, Q.L.; Peng, L.; Xu, Y.F.; Zhou, Y.J.; Guo, F.; Zhang, Y.; Deng, C.; Li, W.G. Effect of 60Co-γ ray and electron beam irradiation on microbial property and qualities of black broken tea. Food Mach. 2020, 36, 148–153. [Google Scholar] [CrossRef]
  23. Zheng, Q.; Tian, W.H.; Yue, L.; Yan, W.Q.; Chen, Z.J.; Zhang, Y.Y.; Kong, Q.L. Aging acceleration effect of electron beam irradiation on Luzhou-flavor Baijiu using electronic nose and electronic tongue. Food Mach. 2025, 41, 36–41. [Google Scholar] [CrossRef]
  24. Nemtanu, M.R.; Brasoveanu, M.; Grecu, M.N.; Minea, R. Green coffee decontamination by electron beam irradiation. Nucl. Instrum. Methods Phys. Res. B 2005, 240, 83–86. [Google Scholar] [CrossRef]
  25. Salari, M.; Khatami, M. Simultaneous application of electron beam irradiation and freezing as an effective method for shelf life extension of minced turkey meat. Food Sci. Nutr. 2025, 13, e4752. [Google Scholar] [CrossRef] [PubMed]
  26. GB 4789.2-2022; Chinese National Standard. National Food Safety Standard-Sood Microbiological Examination: Enumeration of Total Colony Counts. Generally Administration of Quality Supervision: Beijing, China, 2022.
  27. GB 4789.15-2016; Chinese National Standard. National Food Safety Standard-Food Microbiological Examination: Enumeration of Molds and Yeasts. Generally Administration of Quality Supervision: Beijing, China, 2016.
  28. GB 5009.229-2016; Chinese National Standard. National Food Safety Standard-Determination of Acid Value in Foods”, Method 1: Cold Solvent Indicator Titration. Generally Administration of Quality Supervision: Beijing, China, 2016.
  29. GB 5009.227-2023; Chinese National Standard. National Food Safety Standard-Determination of Peroxide Value in Foods”, Method 1: Indicator Titration Method. Generally Administration of Quality Supervision: Beijing, China, 2023.
  30. Getachew, M.; Tolassa, K.; De Frenne, P.; Verheyen, K.; Tack, A.J.M.; Hylander, K.; Ayalew, B.; Boeckx, P. The relationship between elevation, soil temperatures, soil chemical characteristics, and green coffee bean quality and biochemistry in southwest Ethiopia. Agron. Sustain. Dev. 2022, 42, 61. [Google Scholar] [CrossRef]
  31. Huang, G.R.; Liu, S.M.; Chen, G.L.; Zhao, Y.; Huang, Q.L.; Cen, Q.Q.; Ren, E.F. Effects of Harvesting Periods and cultivar on the physicochemical and sensory properties of two coffee bean varieties. Foods 2025, 14, 3135. [Google Scholar] [CrossRef]
  32. Tantapakul, C.; Krobthong, S.; Jakkaew, P.; Sittisaree, W.; Aonbangkhen, C.; Yingchutrakul, Y. Potential of arabica coffee beans from northern Thailand: Exploring antidiabetic metabolites through liquid chromatography with tandem mass spectrometry (LC-MS/MS) Metabolomic Profiling across Diverse Postharvest Processing Techniques. Foods 2023, 12, 3893. [Google Scholar] [CrossRef]
  33. Ren, E.F.; Niu, D.B.; Li, G.; Huang, Y.T.; Huang, X.T.; Li, J.Q.; Chen, G.L. Comparison analysis of sensory quality of vacuum concentrated Orah Mandarin juice under different vacuum concentration methods. Mod. Food Sci. Technol. 2025, 41, 244–254. [Google Scholar] [CrossRef]
  34. Cotter, A.R.; Hopfer, H. The effects of storage temperature on the aroma of whole bean arabica coffee evaluated by coffee consumers and HS-SPME-GC-MS. Beverages 2018, 4, 68. [Google Scholar] [CrossRef]
  35. Khan, A.N.; Pandey, A.K.; Malik, N.E.H.; Bagla, H.K. Understanding the effects of electron-beam irradiation of honey on its biochemical properties. Radiat. Phys. Chem. 2026, 238, 113203. [Google Scholar] [CrossRef]
  36. Luo, X.H.; Li, Y.L.; Yang, D.; Xing, J.L.; Li, K.; Yang, M.; Wang, R.; Wang, L.; Zhang, Y.W.; Chen, Z.X. Effects of electron beam irradiation on storability of brown and milled rice. J. Stored Prod. Res. 2019, 81, 22–30. [Google Scholar] [CrossRef]
  37. Ren, B.; Zhai, Y.H.; Wan, Y.; Li, D.M.; Luo, X.H. Influence of electron beam irradiation on storage stability and sensory properties of brown rice. J. Cereal. Sci. 2025, 121, 104102. [Google Scholar] [CrossRef]
  38. Zhao, Y.; Yu, H.L.; Li, H.H.; Qiu, Y.; Xia, S.Y.; Zhang, J.; Zhu, J.J. Effect of E-beam irradiation on the qualitative attributes of shrimp (Penaeus vannamei). Food Biosci. 2023, 52, 102350. [Google Scholar] [CrossRef]
  39. Li, D.M.; Wan, Y.; Zhang, J.Y.; Zhang, Y.W.; He, R.; Sang, S.Y.; Xing, J.L.; Luo, X.H. Effect of electron beam irradiation on edible quality main tenance of high moisture rice grains. J. Cereal. Sci. 2025, 121, 104104. [Google Scholar] [CrossRef]
  40. Zhai, Y.H.; Pan, L.H.; Luo, X.H.; Zhang, Y.W.; Wang, R.; Chen, Z.X. Effect of electron beam irradiation on storage, moisture and eating properties of high-moisture rice during storage. J. Cereal. Sci. 2022, 103, 103407. [Google Scholar] [CrossRef]
  41. Meng, A.L.; Zhang, Y.J.; Wu, K.Y.; Jia, X.; Chen, H.; Sun, Q.; Gao, P. Study on the effect of high-energy electron beam irradiation on the quality of Tibetan Medicine Shiliu Jianwei San. J. Nucl. Agric. Sci. 2024, 8, 1496–1505. [Google Scholar] [CrossRef]
  42. Zhang, L.L.; Pan, L.N.; Chen, X.M.; Xu, D.F.; Wang, X.B.; Zhou, R.; Ali, I.; Wang, B.S.; Gao, P.; Huang, M.; et al. Analysis of aroma component changes and identification of irradiation markers in Luzhou-flavor liquor within one year after electron beam irradiation. Food Chem. X 2025, 27, 102349. [Google Scholar] [CrossRef] [PubMed]
  43. Pan, L.H.; Xing, J.L.; Zhang, H.; Luo, X.H.; Chen, Z.X. Electron beam irradiation as a tool for rice grain storage and its effects on the physicochemical properties of rice starch. Int. J. Biol. Macromol. 2020, 164, 2915–2921. [Google Scholar] [CrossRef]
  44. Cong, S. Effect of Lipid Oxidation on Flavor Quality Deterioration of Raw Coffee Beans During Storage. Master’s Thesis, Heilongjiang Bayi Agricultural University, Daqing, China, 2020. [Google Scholar]
  45. Xiao, M.; Feng, H.; Chen, L.Y.; Dong, S.B.; Pan, L.; Pan, W.Q.; Huang, Q. Feasibility study on the degradation of aflatoxin B1 in Pu’er tea by electron beam irradiation. Sichuan Agric. Sci. Technol. 2021, 9, 58–61. [Google Scholar]
  46. Wang, G.; Wang, D.; He, Y.; Fu, M.; Tang, Y.W.; Qing, C.; Gao, P.; Huang, M. Research on Electron Beam Irradiation Sterilization Process for Dried Herbs of Ophiopogon japonicus and Rhubarb. J. Nucl. Agric. Sci. 2022, 8, 1579–1588. [Google Scholar] [CrossRef]
  47. Khattak, K.F.; Simpson, T.J. Effect of gamma irradiation on the extraction yield, total phenolic content and free radical-scavenging activity of Nigella staiva seed. Food Chem. 2008, 4, 967–972. [Google Scholar] [CrossRef]
  48. Barbosa, M.D.S.G.; Scholz, M.B.D.S.; Kitzberger, C.S.G.; Benassi, M.D.T. Correlation between the composition of green Arabica coffee beans and the sensory quality of coffee brews. Food Chem. 2019, 292, 275–280. [Google Scholar] [CrossRef]
  49. Wang, H.Y.; Pu, J.Z.; Yan, L.; Zhang, Q.L.; Zhang, Y.Z. Before and after electron beam irradiation of Thesii Herba based on UPLC characteristic chromatogram and quantitative index components. Chin. Med. Res. Pract. 2024, 38, 53–59. [Google Scholar] [CrossRef]
  50. Jia, W.; Li, Y.L.; Du, A.; Fan, Z.B.; Zhang, R.; Shi, L.; Luo, C.X.; Feng, K.Y.; Chang, J.; Chu, X.G. Foodomics analysis of natural aging and gamma irradiation maturation in Chinese distilled baijiu by UPLC-Orbitrap-MS/MS. Food Chem. 2020, 315, 126308. [Google Scholar] [CrossRef] [PubMed]
  51. Wei, F.F.; Tanokura, M. Changes in coffee beans during roasting. In Coffee in Health and Disease Prevention; Elsevier: Amsterdam, The Netherlands, 2025; pp. 125–137. [Google Scholar] [CrossRef]
  52. Angeloni, S.; Mustafa, A.M.; Abouelenein, D.; Alessandroni, L.; Acquaticci, L.; Nzekoue, F.K.; Petrelli, R.; Sagratini, G.; Vittori, S.; Torregiani, E.; et al. Characterization of the Aroma Profile and Main Key Odorants of Espresso Coffee. Molecules 2021, 26, 3856. [Google Scholar] [CrossRef] [PubMed]
  53. Liu, C.; Yang, N.; Yang, Q.; Ayed, C.; Linforth, R.; Fisk, I.D. Enhancing Robusta coffee aroma by modifying flavour precursors in the green coffee bean. Food Chem. 2019, 281, 8–17. [Google Scholar] [CrossRef] [PubMed]
  54. Wu, Y.Y.; Luo, S.; Song, Y.; He, L.M.; Li, F.; Yang, Y.; Wei, M.X.; Luo, X. Analysis of flavor quality differences between LZ coffee and coffee based on untargeted metabolomics. Food Biosci. 2025, 68, 106514. [Google Scholar] [CrossRef]
  55. He, J.; Chen, Q.; Jia, X.; Wang, Y.; Huang, M.; Wang, G.X.; Chen, H.; Gao, P. The effects of gamma irradiation and natural aging on the composition of Nongxiangxing Baijiu. Food Process. Preserv. 2022, 46, e17146. [Google Scholar] [CrossRef]
  56. Wang, X.; Wang, L.Y.; Yu, J.T.; Teng, Y.F.; Xiang, X.M.; Zhang, D.; Kang, L.Y.; Niu, Y.B.; Feng, X.C.; Chen, L. Effect of electron beam irradiation on the quality of chicken during post-mortem ageing. Food Chem. 2025, 480, 143869. [Google Scholar] [CrossRef]
Foods 15 00815 g001
Figure 1. Content of major characteristic components in GCBs (A) and RCBs (B). Different lowercase letters indicate significant differences between the samples of different doses (p < 0.05). CK was equivalent to a 0 kGy treatment of the samples.
Figure 1. Content of major characteristic components in GCBs (A) and RCBs (B). Different lowercase letters indicate significant differences between the samples of different doses (p < 0.05). CK was equivalent to a 0 kGy treatment of the samples.
Foods 15 00815 g001
Foods 15 00815 g002
Figure 2. Effect of irradiation on coffee extraction yield and pH. Different lowercase letters indicate significant differences between the samples of different doses (p < 0.05). CK was equivalent to a 0 kGy treatment of the samples.
Figure 2. Effect of irradiation on coffee extraction yield and pH. Different lowercase letters indicate significant differences between the samples of different doses (p < 0.05). CK was equivalent to a 0 kGy treatment of the samples.
Foods 15 00815 g002
Foods 15 00815 g003
Figure 3. Radar chart of electronic nose sensor responses. CK was equivalent to a 0 kGy treatment of the samples. Performance description of electronic nose sensors: W1C is sensitive to aromatic compounds. W5S is highly sensitive to nitrogen oxides. W3C is sensitive to ammonia and aromatic substances. W6S is primarily selective toward hydrides. W5C is sensitive to short-chain alkanes and aromatic compounds. W1S is sensitive to methyl-containing substances. W1W is sensitive to inorganic sulfides and terpenes. W2S is sensitive to alcohols, aldehydes, and ketones. W2W is sensitive to organic sulfides, aromatic components, and terpenes. W3S is sensitive to long-chain alkanes and high-concentration alkanes.
Figure 3. Radar chart of electronic nose sensor responses. CK was equivalent to a 0 kGy treatment of the samples. Performance description of electronic nose sensors: W1C is sensitive to aromatic compounds. W5S is highly sensitive to nitrogen oxides. W3C is sensitive to ammonia and aromatic substances. W6S is primarily selective toward hydrides. W5C is sensitive to short-chain alkanes and aromatic compounds. W1S is sensitive to methyl-containing substances. W1W is sensitive to inorganic sulfides and terpenes. W2S is sensitive to alcohols, aldehydes, and ketones. W2W is sensitive to organic sulfides, aromatic components, and terpenes. W3S is sensitive to long-chain alkanes and high-concentration alkanes.
Foods 15 00815 g003
Foods 15 00815 g004aFoods 15 00815 g004b
Figure 4. The ratio of compounds related to chemical reactions (A), histogram of the percentage content (B) and major compounds of volatile compounds in coffee (C). Percentages may not sum to 100% due to rounding.
Figure 4. The ratio of compounds related to chemical reactions (A), histogram of the percentage content (B) and major compounds of volatile compounds in coffee (C). Percentages may not sum to 100% due to rounding.
Foods 15 00815 g004aFoods 15 00815 g004b
Table 1. Changes in moisture content and color of GCBs during storage 1.
Table 1. Changes in moisture content and color of GCBs during storage 1.
SampleTime/dMoisture/%L* a* b* ΔE
CK06.21 ± 0.163 aA54.69 ± 1.082 aB2.94 ± 0.123 bB11.63 ± 0.212 abB0 aC
75.95 ± 0.235 aAB53.13 ± 0.38 abC3.65 ± 0.325 abA11.70 ± 0.212 bB1.75 ± 0.309 bB
305.56 ± 0.455 aB56.90 ± 0.557 aA3.28 ± 0.320 cAB13.26 ± 0.516 bcA2.78 ± 0.740 abA
2 kGy06.31 ± 0.170 aA54.41 ± 0.436 aAB2.90 ± 0.170 bA11.49 ± 0.423 bB0.55 ± 0.300 aA
75.68 ± 0.401 aAB53.20 ± 0.785 abB3.10 ± 0.038 bA11.53 ± 0.317 abB1.55 ± 0.693 bA
305.29 ± 0.44 aB54.63 ± 0.733 bA3.50 ± 0.277 bcA12.95 ± 0.308 cA2.00 ± 0.628 bA
4 kGy06.27 ± 0.185 aA53.55 ± 0.724 aB2.98 ± 0.206 abB11.49 ± 0.319 bB1.23 ± 0.605 aB
75.75 ± 0.405 aAB52.52 ± 0.572 abB3.84 ± 0.075 abA11.89 ± 0.274 aB2.38 ± 0.537 abA
305.46 ± 0.056 aB55.60 ± 0.490 abA3.58 ± 0.320 bcA13.72 ± 0.118 abA2.41 ± 0.163 abA
6 kGy06.25 ± 0.227 aA53.28 ± 0.973 aB3.08 ± 0.156 abB12.04 ± 0.341 abB1.59 ± 0.759 aA
75.67 ± 0.06 aAB52.03 ± 0.658 bB3.83 ± 0.150 abA11.83 ± 0.564 abB2.86 ± 0.578 aA
305.33 ± 0.188 aB55.53 ± 0.811 abA3.54 ± 0.188 bcA13.57 ± 0.413 bA2.26 ± 0.641 abA
8 kGy06.50 ± 0.241 aA53.69 ± 0.782 aB3.29 ± 0.083 aB12.31 ± 0.387 aB1.40 ± 0.433 aB
75.98 ± 0.143 aB53.34 ± 0.208 abB3.94 ± 0.116 aA12.09 ± 0.107 bB1.76 ± 0.114 bB
305.11 ± 0.26 aC55.47 ± 1.133 abA4.11 ± 0.096 aA14.21 ± 0.113 aA3.07 ± 0.172 aA
10 kGy06.16 ± 0.093 aA54.08 ± 0.445 aA3.17 ± 0.228 abB11.86 ± 0.423 abC0.76 ± 0.519 aB
75.52 ± 0.393 aB53.68 ± 1.111 aA4.12 ± 0.172 aA12.66 ± 0.106 aB2.02 ± 0.564 abA
305.08 ± 0.146 aB55.23 ± 1.248 abA3.94 ± 0.070 abA13.73 ± 0.131 abA2.70 ± 0.225 abA
1 Different lowercase letters indicate significant differences between different doses among samples of the same storage time (p < 0.05). Different uppercase letters indicate significant differences among the three storage times at the same dose (p < 0.05).
Table 2. Microbial content of GCBs during accelerated storage 1.
Table 2. Microbial content of GCBs during accelerated storage 1.
SampleTime/dMicrobial Counts/(CFU/g)
Total Bacterial CountThe Counts of Mold and Yeast Bacteria
CK06.4 × 1041.9 × 105
72.1 × 1043.8 × 104
303.7 × 1032.5 × 103
2 kGy05.5 × 1038.6 × 103
7ND100
30ND100
4 kGy0ND100
7NDND
30NDND
6, 8, 10 kGy0NDND
7NDND
30NDND
1 CK-0 was equivalent to a 0 kGy treatment and 0 d accelerated storage of the samples. ND indicates not detected.
Table 3. Lipid indicators of GCB after 30 days of ALST 1.
Table 3. Lipid indicators of GCB after 30 days of ALST 1.
SampleCrude fat Content/%Acid Value/(mg/g)Peroxide Value/(g/100 g)
CK-09.08 ± 0.886 b1.31 ± 0.041 e0.12 ± 0.026 d
CK-3010.82 ± 0.991 a1.41 ± 0.051 e0.22 ± 0.040 bc
2 kGy9.47 ± 1.072 ab2.60 ± 0.054 a0.21 ± 0.028 bc
4 kGy10.07 ± 0.935 ab2.34 ± 0.126 bc0.27 ± 0.029 a
6 kGy9.76 ± 0.606 ab2.14 ± 0.085 cd0.31 ± 0.023 a
8 kGy9.70 ± 0.990 ab2.40 ± 0.276 ab0.22 ± 0.032 b
10 kGy9.48 ± 0.473 ab2.12 ± 0.065 d0.17 ± 0.030 cd
1 Different lowercase letters indicate significant differences between the samples of different doses (p < 0.05). CK-0 was equivalent to a 0 kGy treatment and 0 d accelerated storage of the samples. CK-30 was equivalent to a 0 kGy treatment and 30 d accelerated storage of the samples.
Table 4. Electronic nose responses of GCB samples 1.
Table 4. Electronic nose responses of GCB samples 1.
W1CW5SW3CW6SW5CW1SW1WW2SW2WW3S
CK0.76 ± 0.019 a4.54 ± 0.828 a0.99 ± 0.003 a1.00 ± 0.026 a0.73 ± 0.02 a1.76 ± 0.104 b8.43 ± 1.156 a1.38 ± 0.044 b7.43 ± 0.845 a0.99 ± 0.005 c
2 kGy0.74 ± 0.001 ab5.15 ± 0.153 a0.98 ± 0.001 abc1.04 ± 0.06 a0.71 ± 0.002 ab1.89 ± 0.055 ab8.91 ± 0.234 a1.43 ± 0.01 ab7.94 ± 0.164 a0.99 ± 0.002 bc
4 kGy0.71 ± 0.018 b5.84 ± 0.73 a0.98 ± 0.001 bc1.00 ± 0.004 a0.69 ± 0.018 b2.00 ± 0.085 a9.59 ± 0.831 a1.50 ± 0.062 a8.54 ± 0.708 a0.99 ± 0.001 ab
6 kGy0.72 ± 0.020 b5.59 ± 0.836 a0.98 ± 0.002 bc1.00 ± 0.008 a0.69 ± 0.022 ab2.03 ± 0.057 a9.15 ± 0.799 a1.50 ± 0.039 a8.15 ± 0.68 a0.99 ± 0.001 bc
8 kGy0.73 ± 0.008 ab5.02 ± 0.174 a0.98 ± 0.001 ab1.01 ± 0.019 a0.71 ± 0.006 ab1.91 ± 0.039 ab8.51 ± 0.212 a1.45 ± 0.02 ab7.56 ± 0.161 a0.99 ± 0.001 bc
10 kGy0.72 ± 0.029 b5.61 ± 1.075 a0.98 ± 0.003 c1.04 ± 0.048 a0.69 ± 0.029 b2.00 ± 0.131 a9.11 ± 1.03 a1.49 ± 0.08 a8.02 ± 0.828 a1.00 ± 0.002 a
1 Different lowercase letters indicate significant differences between the samples of different doses (p < 0.05).
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Tian, C.; Zhao, Y.; Huang, Q.; Huang, G.; Liu, S.; Cen, Q.; Niu, D.; Ren, E.-F. Evaluating the Effects of Electron Beam Irradiation on Coffee Beans and Their Storage Quality. Foods 2026, 15, 815. https://doi.org/10.3390/foods15050815

AMA Style

Tian C, Zhao Y, Huang Q, Huang G, Liu S, Cen Q, Niu D, Ren E-F. Evaluating the Effects of Electron Beam Irradiation on Coffee Beans and Their Storage Quality. Foods. 2026; 15(5):815. https://doi.org/10.3390/foods15050815

Chicago/Turabian Style

Tian, Chengpiao, Yuan Zhao, Qiulan Huang, Guanru Huang, Shuaimin Liu, Qingjing Cen, Debao Niu, and Er-Fang Ren. 2026. "Evaluating the Effects of Electron Beam Irradiation on Coffee Beans and Their Storage Quality" Foods 15, no. 5: 815. https://doi.org/10.3390/foods15050815

APA Style

Tian, C., Zhao, Y., Huang, Q., Huang, G., Liu, S., Cen, Q., Niu, D., & Ren, E.-F. (2026). Evaluating the Effects of Electron Beam Irradiation on Coffee Beans and Their Storage Quality. Foods, 15(5), 815. https://doi.org/10.3390/foods15050815

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop