Effects of high-humidity hot air impingement steaming on Gastrodia elata: steaming degree, weight loss, texture, drying kinetics, microstructure and active components

Optimizing color enhancement in dried Penaeus vannamei through high-humidity hot air impingement cooking: Enzyme inactivation, reduced drying time, and Maillard reaction inhibition

This study was aimed to evaluate the potential of high-humidity hot air impingement cooking (HHAIC) on Penaeus vannamei, focusing on its drying characteristics, microstructure, water distribution, enzyme activity, astaxanthin content, antioxidant capacity, color, and Maillard reaction. Results demonstrated that a 3 min HHAIC significantly improved the shrimp's color and optimized astaxanthin content with a notable increase in scavenging capacity based on an in-vitro as antioxidation activity evaluation. Compared to the untreated samples, HHAIC could significantly inactivate polyphenol oxidase by 95.76%. Also, it suppressed the Maillard reaction by decreasing 5-hydroxymethylfurfural content and shortened the drying time by 40%. In addition, the low-field nuclear magnetic resonance and microstructure analysis showed alterations in the shrimp muscle fiber structure and water distribution. This study indicated that HHAIC could elevate quality, enhance appearance, and reduce the processing time of dried shrimp, presenting valuable implications for industry progress.

E-eye and FT-NIR combined with multivariate algorithms to rapidly evaluate the dynamic changes in the quality of Gastrodia elata during steaming process

Gastrodia elata (GE) is traditionally subjected to steaming, and steaming duration plays a crucially important role in determining GE quality. This study examined the variations in bioactive components during the steaming process and proposed the utilization of electronic eye and Fourier Transform near-infrared (FT-NIR) spectroscopy for quality assessment. The findings revealed that the levels of parishin E parishin B, parishin A, and gastrodin initially rose and subsequently declined, while 4-Hydroxybenzyl alcohol exhibited a rapid decrease followed by stabilization. With prolonged steaming, the brightness of GE decreased, while the red and yellow tones became more pronounced and the color saturation increased. FT-NIR divided the steaming process into three stages: 0 min (raw GE), 0-9 min (partially steamed GE), and 9-30 min (fully steamed GE), and the partial least squares regression models effectively predicted the levels of five components. Overall, this study provided valuable insights into quality control in food processing.

High-humidity hot-air impingement blanching conditions for the inhibition of potato-browning enzymes and for quality retention

BACKGROUND

Potato is an important non-cereal crop. It provides carbohydrates, a major source of energy in the human diet. Blanching during the processing of fresh fruits and vegetables is essential for their preservation. High-humidity hot-air impingement blanching (HHAIB) is a promising emerging technology for pretreating different food materials. This research aimed to identify the optimum HHAIB conditions for the inhibition of potato-browning enzymes, maintaining their nutritional and physical quality, and to compare this with conventional hot-water blanching (HWB).

RESULTS

Polyphenol oxidase (PPO) inactivation, total phenol content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, color, textural attributes, thermal properties, microstructure, and particles crystallinity were evaluated. The relative humidity (RH), temperature, and duration of HHAIB required for PPO inactivation (2.59%) were 50%, 105 °C, and 4 min, respectively, which resulted in a complete gelatigination of potato starches, based on the thermal properties and the microstrcture of the blanched potatoes. These conditions led to improvements in TPC to 312.54 μg GAE.g-1 FP, DPPH scavenging to 1.99 μmol TE.g-1 FP, as well as enhancements in color and crystallinity. When HHAIB was conducted at lower temperatures (85 and 95 °C) there were negative effects on the blanched potatoes' color and crystallinity, along with a non-safe level of PPO activity.

CONCLUSION

High-humidity hot-air impingement blanching was superior to HWB, inhibiting PPO, maintaining nutrients, and preserving physical properties, especially under the optimum conditions revealed by the principal component analysis. It provides an excellent technique for blanching and pretreating potatoes, preserving them, and maintaining their quality. © 2023 Society of Chemical Industry.

Design and Experiment of Combined Infrared and Hot-Air Dryer Based on Temperature and Humidity Control with Sea Buckthorn (Hippophae rhamnoides L.)

A drying device based on infrared radiation heating technology combined with temperature and humidity process control technology was created to increase the drying effectiveness and quality of sea buckthorn. Based on the conventional k-turbulence model, the velocity field in the air distribution chamber was simulated using COMSOL 6.0 software. The airflow of the drying medium in the air distribution chamber was investigated, and the accuracy of the model was verified. Given that the inlet of each drying layer in the original model had a different velocity, the velocity flow field was improved by including a semi-cylindrical spoiler. The results showed that installation of the spoiler improved the homogeneity of the flow field for various air intakes, as the highest velocity deviation ratio dropped from 26.68% to 0.88%. We found that sea buckthorn dried more rapidly after being humidified, reducing the drying time by 7.18% and increasing the effective diffusion coefficient from 1.12 × 10^-8 to 1.23 × 10^-8 m²/s. The L*, rehydration ratio, and vitamin C retention rate were greater after drying with humidification. By presenting this hot-air drying model as a potential high-efficiency and high-quality preservation technology for sea buckthorn, we hope to advance the development of research in the sea buckthorn drying sector.

Effects of Different Blanching Methods on the Quality of Tremella fuciformis and Its Moisture Migration Characteristics

Blanching is a critical step in the processing of Tremella fuciformis (T. fuciformis). The effects of different blanching methods (boiling water blanching (BWB), ultrasonic-low temperature blanching (ULTB), and high-temperature steam (HTS)) on the quality and moisture migration characteristics of T. fuciformis were investigated. The results showed that the T. fuciformis blanched by ULTB (70 °C, 2 min, 40 kHz, 300 W) had the best quality, including a brighter appearance, superior texture, and good sensory features, with a polysaccharide content of 3.90 ± 0.02%. The moisture migration characteristics of T. fuciformis after blanching exhibited four peaks, displayed strong and weak chemically bound water, immobilized water, and free water, whereas ULTB had a weak effect on the freedom of water in T. fuciformis. The study will provide the foundation for the factory processing of T. fuciformis.

Effects of Steam and Water Blanching on Drying Characteristics, Water Distribution, Microstructure, and Bioactive Components of Gastrodia Elata

In the current work, the effects of steam and boiling water blanching on the drying characteristics, water distribution, microstructure, and contents of bioactive substances of Gastrodia elata (G. elata) were explored. Results showed that the degree of steaming and blanching was related to the core temperature of G. elata. The steaming and blanching pretreatment increased the drying time of the samples by more than 50%. The low-field nuclear magnetic resonance (LF-NMR) of treated samples showed that the relaxation time corresponded to water molecule states (bound, immobilized, and free) and G. elata became shorter, which indicated a reduction in free moisture and increased resistance of water diffusion in the solid structure during drying. Hydrolysis of polysaccharides and gelatinization of starch granules was observed in the microstructure of treated samples, which was consistent with changes in water status and drying rates. Steaming and blanching increased gastrodin and crude polysaccharide contents and decreased p-hydroxybenzyl alcohol content. These findings will contribute to a better understanding of the effect of steaming and blanching on the drying behavior and quality attributes of G. elata.

Components research on Tetrastigma hemsleyanum Diels et Gilg: identification and effect of drying methods on the content of ten main constituents by targeting metabolomics method

Tetrastigma hemsleyanum Diels et Gilg (TH) is one of the new eight Genuine Medicinal Materials of Zhejiang. It has extensive biological activities, such as anti-inflammatory, anti-tumor and analgesic activities, etc. In this study, the chemical components of TH were systematically investigated by ultra high-performance liquid chromatography-tandem quadrupole time of flight mass spectrometry (UPLC/Q-TOF-MS). Based on the MS spectrum, 39 compounds in TH extracts including 14 flavonoids, 10 fatty acids, 5 polyphenols and phenolic acids, 4 terpenes and other compounds were detected and tentatively identified. TH samples were treated under different drying methods (vacuum freeze drying, hot air drying, natural drying, light drying and vacuum drying). Besides, the effect of different drying methods on the content of 10 main chemical constituents in TH extracts including catechin, rutin, kaempferol-3-O-rutinoside and so on was also investigated by targeting metabolomics method with ultra high-performance liquid chromatography-tandem triple quadrupole mass spectrometry (UPLC-MS/MS) assisted by multivariate statistical analysis. Large differences were observed between vacuum drying and vacuum freeze drying with remarkable content changes. The contents of rutin, proanthocyanidin B1 and catechin were the most different among the various drying methods. The systematic identification of chemical constituents is helpful for the further medicinal development and application of TH. The effects of drying methods on the content of TH components were studied, which provided experimental data for the processing, storage and quality control of TH.

Evaluate how steaming and sulfur fumigation change the microstructure, physicochemical properties and in vitro digestibility of Gastrodia elata Bl. starch

The sulfur dioxide gas (SO₂) generated by sulfur burning can improve the appearance quality of food and enhance the storage time. However, excessive sulfur dioxide will pollute the environment and cause deterioration of food quality, and even the high residual levels can increase the risk of cancer. As Gastrodia elata Blume is prone to corruption during processing, sulfur fumigation is often used for preservation. In this study, spectral analysis and Texture Profile Analysis (TPA) were used to investigate the effects of traditional sulfur fumigation processing on the morphology quality, edible quality and structural characteristics of G. elata. The results showed that compared with direct drying, the pH decreased by 0.399 of the sulfur fumigated after steamed treatment G. elata, and the morphology quality, pasting ability and gel edible quality of the starch were significantly improved. In addition, it was suggested that sulfur fumigation after steaming could promote the release of molecular chains from starch granules and thus enhance the cross-linking between molecules, which explained the reason for the improve of starch edible quality. This study can provide technical and theoretical support for improving the quality of starch rich foods, replacing sulfur fumigation and reducing potential environmental hazards.

Revealing color change and drying mechanisms of pulsed vacuum steamed Cistanche deserticola through bioactive components, microstructural and starch gelatinization properties

Cistanche deserticola is a famous herbal medicine and has been used worldwide for its kidney-tonifying and anti-aging values. This study investigated the effects of pulsed vacuum steaming (PVS) on bioactive phenylethanoid glycosides (PhGs), total soluble sugars, polysaccharides, color, drying characteristics, microstructure, and starch gelatinization properties of Cistanche deserticola. PVS pretreatment significantly increased PhGs and soluble sugar content while reduced the polysaccharides content. And increasing the material core temperature to 75 °C at the largest diameter was proposed as the optimal steaming condition and the PhGs content was increased by 1.11 times compared with that by atmospheric steaming. The color of steamed samples changed to oily black due to Maillard reaction. PhGs content was significantly (P < 0.05) positively correlated with total color difference (ΔE). Steaming until the ΔE value of 15.95 could achieve the maximum accumulation of PhGs, corresponding to the highest increasing ratio of echinacoside and acteoside. Starch was completely gelatinized and formed a barrier layer adhering to the cell surface when the material core temperature reached 75 °C at the largest diameter, explaining why after steaming the Cistanche deserticola drying time was prolonged by 85.71 %. The study can provide an innovative steaming technology and optimal process parameters for obtaining high-quality Cistanche deserticola decoction pieces, as well as propose a non-destructive testing method to quickly predict PhGs content based on color parameters during the steaming process.

Effect of High-Humidity Hot Air Impingement Steaming on Cistanche deserticola Slices: Drying Characteristics, Weight Loss, Microstructure, Color, and Active Components

Cistanche deserticola is one of the most precious herbal medicines and is widely used in the pharmaceutical and healthy food industries. Steaming is an important step prior to drying in the processing of C. deserticola. This research investigated the effects of high-humidity hot air impingement steaming (HHAIS) parameters such as temperature, time, and relative humidity (RH) on drying characteristics, weight loss, color, microstructure, and active components of C. deserticola slices. The results showed that the steaming process caused a weight loss in C. deserticola; however, increasing the RH reduced the weight loss. Starch gelatinization observed from the microstructure of the steamed samples explained their long drying time. The Page model can well fit the drying process with a high R² (>0.956) under the drying conditions of 60°C and 6 m/s. Steaming increased the content of phenylethanoid glycosides, and the highest content was obtained at 95°C and 60% RH for 20 min, 75°C and 70% RH for 20 min, and 75°C and 60% RH for 30 min. The steamed samples appeared in an oil black color. When the color difference (ΔE) values were in the range of 16.79–20.12, the contents of echinacoside and acteoside reached the maximum. Steaming at 95°C and 60% RH for 20 min, 75°C and 70% RH for 20 min, and 75°C and 60% RH for 30 min are the optimum process conditions. The results from this work provide innovative steaming technology and suitable processing parameters for producing C. deserticola decoction pieces with a high quality, which will broaden its potential application in the functional health food industry.

Widely Targeted Metabolomics Analysis to Reveal Transformation Mechanism of Cistanche Deserticola Active Compounds During Steaming and Drying Processes

Cistanche deserticola is one of the most precious plants, traditionally as Chinese medicine, and has recently been used in pharmaceutical and healthy food industries. Steaming and drying are two important steps in the processing of Cistanche deserticola. Unfortunately, a comprehensive understanding of the chemical composition changes of Cistanche deserticola during thermal processing is limited. In this study, ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS)-based widely targeted metabolomics analysis was used to investigate the transformation mechanism of Cistanche deserticola active compounds during steaming and drying processes. A total of 776 metabolites were identified in Cistanche deserticola during thermal processing, among which, 77 metabolites were differentially regulated (p < 0.05) wherein 39 were upregulated (UR) and 38 were downregulated (DR). Forty-seven (17 UR, 30 DR) and 30 (22 UR, 8 DR) differential metabolites were identified during steaming and drying, respectively. The most variation of the chemicals was observed during the process of steaming. Metabolic pathway analysis indicated that phenylpropanoid, flavonoid biosynthesis, and alanine metabolism were observed during steaming, while glycine, serine, and threonine metabolism, thiamine metabolism, and unsaturated fatty acid biosynthesis were observed during drying. The possible mechanisms of the chemical alterations during thermal processing were also provided by the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Furthermore, the blackening of the appearance of Cistanche deserticola mainly occurred in the steaming stage rather than the drying stage, which is associated with the metabolism of the amino acids. All results indicated that the formation of active compounds during the processing of Cistanche deserticola mainly occurred in the steaming stage.

Development of a New Pasta Product by the Incorporation of Chestnut Flour and Bee Pollen

This work aimed at developing fortified pastas incorporating chestnut flour (25–55%) and powdered pollen (5–20%), either separately or in combination, as well as the characterization of the products obtained. To this, a physical characterization was carried out (analyzing texture and color), complemented with chemical analyses to determine the nutritional composition. Results showed that adding chestnut flour over 40% to wheat-flour pasta shortened optimum cooking time and lowered cooking yield, and the addition to pasta prepared with wheat flour and eggs maintained approximately constant the cooking yield. Additionally, the incorporation of pollen powder (up to 20%) in pasta prepared with wheat flour and water or fresh egg shortened the cooking time and cooking yield, in both fresh and dried pasta. The most suitable percentages of the new ingredients were 50% for chestnut and 10% for pollen. Comparing with the control pasta recipe (wheat flour and egg), the addition of chestnut flour (50%) or pollen powder (10%) increased stickiness, adhesiveness and the darkening of the final product (fresh or dried) but maintained the firmness of the pasta. The cooking of fresh or dried pasta enriched with both ingredients turned the pasta clearer and slightly stickier. On the other hand, the addition of chestnut flour and pollen powder in pasta formulation delivered a nutritionally balanced product with high fiber, vitamins and minerals. Overall, chestnut flour and powdered pollen represent promising ingredients for the development of functional fresh and dried pasta formulations.