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1.
Molecules ; 28(7)2023 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-37049695

RESUMEN

Drying is one of the common procedures in the food processing steps. The moisture content (MC) is also of crucial significance in the evaluation of the drying technique and quality of the final product. However, conventional MC evaluation methods suffer from several drawbacks, such as long processing time, destruction of the sample and the inability to determine the moisture of single grain samples. In this regard, the technology and knowledge of hyperspectral imaging (HSI) were addressed first. Then, the reports on the use of this technology as a rapid, non-destructive, and precise method were explored for the prediction and detection of the MC of crops during their drying process. After spectrometry, researchers have employed various pre-processing and merging data techniques to decrease and eliminate spectral noise. Then, diverse methods such as linear and multiple regressions and machine learning were used to model and predict the MC. Finally, the best wavelength capable of precise estimation of the MC was reported. Investigation of the previous studies revealed that HSI technology could be employed as a valuable technique to precisely control the drying process. Smart dryers are expected to be commercialised and industrialised soon by the development of portable systems capable of an online MC measurement.


Asunto(s)
Productos Agrícolas , Imágenes Hiperespectrales , Análisis Espectral/métodos , Desecación/métodos , Manipulación de Alimentos/métodos
2.
Molecules ; 28(24)2023 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-38138578

RESUMEN

Hemp is used as a source of fiber, oil and bioactive substances including volatile and cannabinoid-containing substances. This paper presents, for the first time, results on the evaluation of drying methods (convective, vacuum-microwave and combined convective pre-drying and vacuum-microwave finishing drying) of hemp leaves on the qualitative and quantitative changes in secondary metabolites, including essential oils, cannabinoids and sterols. A ranking and descriptive test of hemp leaves was also performed. Drying kinetics was presented using three models, including logarithmic, Midilli and modified Page. The SPME-Arrow technique was used to determine 41 volatile compounds, of which caryophyllene, ß-myrcene and α-humulene were dominant in dried and fresh leaves. Regarding the essential oils obtained, 64 were identified, with caryophyllene, humulene epoxide II and limonene being the dominant ones. For preserving the highest amount of oils, the best method was the convective pre-drying followed by vacuum-microwave finishing drying (CD60-VMD) combined method, where the retention of volatile compounds was 36.08%, whereas the CD70 and 240-VMD methods resulted in the highest loss of 83%. The predominant cannabinoids in fresh hemp leaves were CBDA 6.05 and CBD 2.19 mg g-1. Drying caused no change in the cannabinoid profile of the plant material. ß-Sitosterol, campesterol and lupeol were dominant in the phytosterol and triterpene fractions. No changes in either quality or quantity were observed in any of the variants found.


Asunto(s)
Cannabinoides , Cannabis , Aceites Volátiles , Cannabis/química , Hojas de la Planta/química , Aceites Volátiles/química , Cannabinoides/química
3.
Molecules ; 25(5)2020 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-32121055

RESUMEN

Apple slices of the Elise variety were previously osmo-dehydrated in erythritol, xylitol, and sucrose for 2 h. In some parts of the experiment, 30 min of ultrasound pre-treatment (US) were applied. Afterwards, fruit samples were dried by convective (CD), microwave-vacuum (VM), and a combined method (CD/VM, mix two of them). The main aim of the research was to characterize an impact of osmotic dehydration, sonication pre-treatment, and drying method on the physicochemical properties of the dried apples. The use of sugar alcohols (xylitol, erythritol) in the production of dried apples did not badly affect the taste of the obtained dried products; it enabled a noticeable cooling/refreshing effect felt in the mouth when consuming a snack, and enabled the production of dried snacks with lower calorific value. Polyol residues in the product were at a level that was safe for consumers. The most popular convective drying was long lasting, whereas the VM drying method allowed for the shortest drying time, amounting to 76 min; moreover, additional application of ultrasounds reduced this time to 36 min. The combined drying method allowed the total duration of the process to be reduced 2-4.5 times. Ultrasound applied during osmotic dehydration did not significantly affect attributes of the descriptive sensory analysis for the obtained dried apples. The best hygroscopic properties, ensuring the storage stability of the dried product, showed dried apples previously osmo-dehydrated in erythritol and sucrose solutions.


Asunto(s)
Frutas/química , Malus/química , Sacarosa/química , Desecación , Ósmosis , Sonicación
4.
Molecules ; 25(22)2020 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-33228079

RESUMEN

Osmotic dehydration (OD) performed in concentrated fruit juices used as osmotic solution (OS) comes with some limitations resulting from the material cell structure and is not entirely recognized at the moment. Filtration of the juice could provide some insight into the phenomena occurring throughout the OD. Therefore, the main aim of the study was to recognize the mechanism of selective penetration during OD and evaluate the effect of filtration on physical and chemical properties of osmo-dehydrated material. For this purpose, OD of pumpkin in non-filtrated and filtrated (filters 0.2, 0.45, 0.8, 1.2, 3, 5 and 8 µm) concentrated chokeberry juice was carried out in the study. Moreover, scanning electron microscope (SEM) images were provided. Total phenolic content (TPC) and antioxidant capacity measured by Ferric Reducing Antioxidant Potential (FRAP) and Trolox Equivalent Antioxidant Capacity (TEAC ABTS) of OS and the material were determined. It was found that even though filtration of osmotic solution had a moderate influence on the mass transfer, it greatly affected the chemical composition of dehydrated material. The best option, considering both chemical and physical properties of the dehydrated material, is the use of non-filtrated solution. However, when shorter time of OD is considered, much better results are obtained for filtrated solutions.


Asunto(s)
Fenómenos Químicos , Desecación , Filtración , Ósmosis , Antioxidantes/análisis , Modelos Teóricos , Polifenoles/análisis , Soluciones
5.
Molecules ; 25(16)2020 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-32785157

RESUMEN

The effect of different drying techniques (freeze, convective, vacuum-microwave and combined drying) on the drying kinetics, the phytochemical compounds and sensory characteristics in loquat cultivar 'Algar' was studied. The convective drying resulted in the highest amount of total hydroxycinnamic acids (5077 mg/kg wet weight (ww)), with 3-caffeoyl quinic acid and 5-caffeoyl quinic acid being the greatest carotenoids. The highest values of total carotenoids were obtained by the freeze-drying technique (2601 mg/kg ww), followed by all convective treatments and vacuum-microwave at 360 W. The highest carotenoid was ß-carotene. The ABTS+• (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) and FRAP (Ferric Ion Reducing Antioxidant Power) values ranged from 2.04 up to 3.27 mmol Trolox/100 g ww, and from 1.89 up to 2.29 mmol Trolox/100 g ww, respectively. As expected, the color difference of freeze-dried samples was the lowest (7.06), similar to combined drying conditions (9.63), whilst the highest value was found after convective drying (37.0). All treatments were sensory acceptable (no off-flavors). However, still, further research is needed to fully optimize these studied drying treatments because the freeze-dried sample still had higher carotenoid content and better instrumental color parameters. Although recently the impact of microwave drying has been studied, this is the first work comparing phytochemical composition of loquat fruit under the different drying methods mentioned above.


Asunto(s)
Carotenoides/análisis , Ácidos Cumáricos/análisis , Eriobotrya/química , Conservación de Alimentos/métodos , Adulto , Antioxidantes/química , Cromatografía Líquida de Alta Presión , Color , Desecación , Eriobotrya/metabolismo , Femenino , Liofilización , Frutas/química , Frutas/metabolismo , Humanos , Masculino , Espectrometría de Masas , Microondas , Persona de Mediana Edad , Umbral Sensorial , Vacio
6.
Molecules ; 24(19)2019 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-31546606

RESUMEN

The aim of this work was to analyse the effect of ultrasound-assisted osmotic dehydration of apples v. Elise on mass transfer parameters, water activity, and colour changes. Ultrasound treatment was performed at a frequency of 21 kHz with a temperature of 40 °C for 30-180 min using four osmotic solutions: 30% concentrated syrups of erythritol, xylitol, maltitol, and dihydroxyacetone (DHA). The efficiency of the used solutes from the polyol groups was compared to reference dehydration in 50% concentrated sucrose solution. Peleg's model was used to fit experimental data. Erythritol, xylitol, and DHA solutions showed similar efficiency to sucrose and good water removal properties in compared values of true water loss. The application of ultrasound by two methods was in most cases unnoticeable and weaker than was expected. On the other hand, sonication by the continuous method allowed for a significant reduction in water activity in apple tissue in all tested solutions.


Asunto(s)
Dihidroxiacetona/química , Malus/química , Polímeros/química , Alcoholes del Azúcar/química , Ósmosis
7.
Molecules ; 24(13)2019 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-31247989

RESUMEN

This study was to present the effect of different parameters of combined methods of drying such as vacuum-microwave (VMD: 480, 120 W), hot air (CDD: 70, 60, 50 °C) and combined methods as pre-drying by CD and finish drying by VMD (CD-VMD: 60 °C + 480/120W) in order to avoid a rapid increase in temperature at the critical moisture content of ca. 1 kg/kg dm (dry mass). Control samples were prepared by freeze-drying (FD). Drying kinetics, including the temperature profile of dried material, as well as on some quality factors of the finished product as phenolic compounds, antioxidant capacity, and color were evaluated. The increase in air temperature during CD as well as the increase in material temperature during VMD deteriorated dried product quality in terms of the content of phenolic compounds, antioxidant activity and color. Dried jujube fruits have a long shelf life and therefore may be a fine alternative to fresh fruit all year round.


Asunto(s)
Antioxidantes/química , Frutas/química , Fenoles/química , Pigmentación , Extractos Vegetales/química , Ziziphus/química , Antioxidantes/farmacología , Liofilización , Cinética , Microondas , Fenoles/farmacología , Extractos Vegetales/farmacología , Temperatura
8.
Molecules ; 24(8)2019 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-31022967

RESUMEN

The preservation of active constituents in Cassia alata through the removal of moisture is crucial in producing a final product with high antioxidant activity. This study aims to determine the influences of various drying methods and drying conditions on the antioxidant activity, volatiles and phytosterols content of C. alata. The drying methods used were convective drying (CD) at 40 °C, 50 °C and 60 °C; freeze drying; vacuum microwave drying (VMD) at 6, 9 and 12 W/g; and two-stage convective pre-drying followed by vacuum microwave finish drying (CPD-VMFD) at 50 °C and 9 W/g. The drying kinetics of C. alata are best described by the thin-layer model (modified Page model). The highest antioxidant activity, TPC and volatile concentration were achieved with CD at 40 °C. GC-MS analysis identified the presence of 51 volatiles, which were mostly present in all samples but with quantitative variation. The dominant volatiles in fresh C. alata are 2-hexenal (60.28 mg 100 g-1 db), 1-hexanol (18.70 mg 100 g-1 db) and salicylic acid (15.05 mg 100 g-1 db). The concentration of phytosterols in fresh sample was 3647.48 mg 100 g-1 db, and the major phytosterols present in fresh and dried samples were ß-sitosterol (1162.24 mg 100 g-1 db). CPD-VMFD was effective in ensuring the preservation of higher phytosterol content in comparison with CD at 50 °C. The final recommendation of a suitable drying method to dehydrate C. alata leaves is CD at 40 °C.


Asunto(s)
Antioxidantes/química , Cassia/química , Aceites Volátiles/química , Compuestos Orgánicos Volátiles/química , Aldehídos/química , Antioxidantes/aislamiento & purificación , Liofilización , Cromatografía de Gases y Espectrometría de Masas , Hexanoles/química , Microondas , Fitosteroles/química , Hojas de la Planta/química , Ácido Salicílico/química , Vacio , Compuestos Orgánicos Volátiles/aislamiento & purificación
9.
Molecules ; 24(7)2019 04 09.
Artículo en Inglés | MEDLINE | ID: mdl-30970652

RESUMEN

The preservation of active constituents in fresh herbs is affected by drying methods. An effective drying method for Strobilanthes crispus which is increasingly marketed as an important herbal tea remains to be reported. This study evaluated the effects of conventional and new drying technologies, namely vacuum microwave drying methods, on the antioxidant activity and yield of essential oil volatiles and phytosterols. These drying methods included convective drying (CD) at 40 °C, 50 °C, and 60 °C; vacuum microwave drying (VMD) at 6, 9, and 12 W/g; convective pre-drying and vacuum microwave finish drying (CPD-VMFD) at 50 °C and 9 W/g; and freeze-drying (FD). GC­MS revealed 33 volatiles, and 2-hexen-1-ol, 2-hexenal, 1-octen-3-ol, linalool, and benzaldehyde were major constituents. The compounds ß-sitosterol and α-linolenic acid were the most abundant phytosterol and fatty acid, respectively, in fresh S. crispus. The highest phenolic content was achieved with CD at 60 °C. The highest antioxidant activity was obtained with CD at 40 °C and VMD at 9 W/g. On the contrary, the highest total volatiles and phytosterols were detected with CD at 50 °C and VMD at 9 W/g, respectively. This study showed that CD and VMD were effective in producing highly bioactive S. crispus. A suitable drying parameter level, irrespective of the drying method used, was an important influencing factor.


Asunto(s)
Acanthaceae/química , Antioxidantes/análisis , Microondas , Fitosteroles/análisis , Liofilización , Vacio
10.
J Food Sci Technol ; 56(5): 2386-2394, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-31168121

RESUMEN

This study aimed to investigate the changes in the total polyphenolic content and antioxidant properties after subjecting Pink Rock Rose (Cistus creticus) leaves to three different drying procedures, including convection drying (CD) at 40, 50 and 60 °C; vacuum-microwave drying (VMD) at 240 W microwave power; and combined drying consisting of convective pre-drying at 50 °C followed by vacuum-microwave finish drying at 240 W microwave power (CPD-VMFD). The total polyphenolic content and antioxidant properties (DPPH, ABTS) of leaves subjected to these three drying methods were spectrophotometrically determined. The results show that convection drying at 40 °C and vacuum-microwave drying yielded dried leaves with the highest bioactive potential in terms of the total polyphenol content and antioxidant activity, with the highest and lowest values of final specific energy consumption, respectively. The lowest bioactive potential was found in a product dried at 60 °C, which can be attributed to the possible degradation or changes in polyphenol structures under high temperatures. During the combined treatment (CPD-VMFD), most of the moisture was efficiently removed from the raw material by CPD, whereas the time of drying was significantly reduced by the application of VMFD. Combined drying CPD-VMFD is most suitable for industrial applications as it produces dried leaves with a bioactive potential that is only slightly lower than that achieved with VMD while providing a high-throughput capacity relative to operating costs.

11.
J Sci Food Agric ; 98(4): 1511-1521, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28802017

RESUMEN

BACKGROUND: One of the best preservation method for long-term storage is drying. In this work, the influence of different drying methods on aroma and sensory profile of shiitake mushroom was evaluated. The drying methods tested were: convective drying (CD), freeze-drying (FD), vacuum-microwave drying (VMD), and a combination of convective pre-drying and vacuum-microwave finish-drying (CPD-VMFD). RESULTS: The volatile composition of fresh and dried shiitake mushrooms was analysed by SPME, GC-MS and GC-FID, and showed the presence of 71 volatile compounds, most of them present in all dried samples but with quantitative variation. The major volatile compounds in fresh shiitake were 1-octen-3-ol (20.2%), 2-octanone (20.7%), 1,2,4-trithiolane (9.8%), and 1,2,3,5,6-pentathiepane (8.2%). Drying of shiitake mushrooms caused significant losses of C8 compounds and cyclic sulfur compounds, such as 1,2,4-trithiolane (V31) and 1,2,4,5-tetrathiane (V57). Samples dried at CD 80 °C implied a relative short drying time (120 min), had the highest contents of total volatiles (1594 µg 100 g-1 ) and cyclic sulfur compounds (e.g. V57 126 µg 100 g-1 ), and the highest intensity of most of the key positive sensory attributes, such as inner colour (7.0), fresh shiitake flavour (6.7), and sponginess (6.2). CONCLUSION: The best dehydration methods, resulting in the highest total concentrations of volatile compounds and high intensity of key sensory attributes were FD (if vacuum and liquid nitrogen facilities are available) and CD at 80 °C (for companies with vacuum and liquid nitrogen facilities). © 2017 Society of Chemical Industry.


Asunto(s)
Aromatizantes/química , Conservación de Alimentos/métodos , Hongos Shiitake/química , Compuestos Orgánicos Volátiles/química , Desecación , Cromatografía de Gases y Espectrometría de Masas , Humanos , Odorantes/análisis , Gusto
12.
J Food Sci Technol ; 55(3): 1074-1082, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29487450

RESUMEN

During the industrial manufacturing of pomegranate juice, large amounts of pomace are produced. The aim of this work was to find the effective method to dry pomegranate pomace to open new commercial applications for this co-product. The effects of three drying methods: (i) convective drying (CD) at 50, 60, and 70 °C; (ii) vacuum microwave drying (VMD) at 240, 360, and 480 W, and (iii) a combined method (CPD-VMFD); convective pre-drying (60 °C) followed by vacuum microwave finish drying (360 W), on drying kinetics and quality of PomP (pomegranate pomace obtained after preparing pomegranate juice by squeezing only arils) were evaluated. The shortest treatments were VMD at 240 and 360 W (52 and 33 min, respectively); besides, these treatments led to interesting values of the green-red coordinate, a*, (12.2 and 4.1, respectively), total phenolic content (4.0 and 4.1 mg eq gallic acid g-1 dry weight, respectively), and antioxidant activity (30.8 and 29.0 µmol g-1 dry weight, respectively). On the other hand, this study demonstrated that this co-product is a rich source of punicic acid (average value = 66.4%), being a good opportunity for the pharmaceutical and nutraceutical industries. Moreover, no significant changes in the fatty acid profile was observed as affected by the drying treatments, and no off-flavors were generated by any of the drying methods.

13.
Int J Mol Sci ; 18(1)2017 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-28106740

RESUMEN

Among popular crops, plum (Prunus domestica L.) has received special attention due to its health-promoting properties. The seasonality of this fruit makes it impossible to consume it throughout the year, so new products in a powder form may offer an alternative to fresh consumption and may be used as high-quality natural food ingredients. A 100% plum (cultivar "Valor") juice was mixed with three different concentrations of maltodextrin or subjected to sugars removal by amberlite-XAD column, and dried using the freeze, spray, and vacuum (40, 60, and 80 °C) drying techniques. The identification and quantification of phenolic acids, flavonols, and anthocyanins in plum powders was performed by LC-MS QTof and UPLC-PDA, respectively. l-ascorbic acid, hydroxymethylfurfural, and antioxidant capacity were measured by the Trolox equivalent antioxidant capacity (TEAC) ABTS and ferric reducing antioxidant potential (FRAP) methods in order to compare the influence of the drying methods on product quality. The results indicated that the profile of polyphenolic compounds in the plum juice powders significantly differed from the whole plum powders. The drying of a sugar free plum extract resulted in higher content of polyphenolic compounds, l-ascorbic acid and antioxidant capacity, but lower content of hydroxymethylfurfural, regardless of drying method applied. Thus, the formulation of plum juice before drying and the drying method should be carefully selected in order to obtain high-quality powders.


Asunto(s)
Antioxidantes/química , Jugos de Frutas y Vegetales/análisis , Polvos/química , Prunus domestica/química , Antocianinas/análisis , Ácido Ascórbico/análisis , Cromatografía Liquida/métodos , Desecación/métodos , Flavonoles/análisis , Frutas/química , Furaldehído/análogos & derivados , Furaldehído/análisis , Espectrometría de Masas/métodos , Fenoles/análisis , Extractos Vegetales/química , Polifenoles/análisis , Polvos/normas , Control de Calidad
14.
Molecules ; 22(12)2017 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-29258186

RESUMEN

The osmotic dehydration (OD) process consists of the removal of water from a material during which the solids from the osmotic solution are transported to the material by osmosis. This process is commonly performed in sucrose and salt solutions. Taking into account that a relatively high consumption of those substances might have a negative effect on human health, attempts have been made to search for alternatives that can be used for osmotic dehydration. One of these is an application of chokeberry juice with proven beneficial properties to human health. This study aimed to evaluate the physicochemical properties of the OD solution (chokeberry juice concentrate) before and after the osmotic dehydration of carrot and zucchini. The total polyphenolics content, antioxidant capacity (ABTS, FRAP), dynamic viscosity, density, and water activity were examined in relation to the juice concentration used for the osmotic solution before and after the OD process. During the osmotic dehydration process, the concentration of the chokeberry juice decreased. Compounds with lower molecular weight and lower antioxidant capacity present in concentrated chokeberry juice had a stronger influence on the exchange of compounds during the OD process in carrot and zucchini. The water activity of the osmotic solution increased after the osmotic dehydration process. It was concluded that the osmotic solution after the OD process might be successfully re-used as a product with high quality for i.e. juice production.


Asunto(s)
Desecación/métodos , Extractos Vegetales/aislamiento & purificación , Cucurbitaceae/química , Daucus carota/química , Depuradores de Radicales Libres/análisis , Frutas/química , Jugos de Frutas y Vegetales , Ósmosis , Extractos Vegetales/química , Prunus/química , Soluciones
15.
Int J Mol Sci ; 18(1)2016 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-28042845

RESUMEN

The seasonality of fruits and vegetables makes it impossible to consume and use them throughout the year, thus numerous processing efforts have been made to offer an alternative to their fresh consumption and application. To prolong their availability on the market, drying has received special attention as currently this method is considered one of the most common ways for obtaining food and pharmaceutical products from natural sources. This paper demonstrates the weakness of common drying methods applied for fruits and vegetables and the possible ways to improve the quality using different drying techniques or their combination with an emphasis on the microwave energy. Particular attention has been drawn to the combined drying with the assistance of vacuum-microwaves. The quality of the dried products was ascribed by chemical properties including the content of polyphenols, antioxidant capacity and volatiles as well as physical parameters such as color, shrinkage, porosity and texture. Both these fields of quality classification were considered taking into account sensory attributes and energy aspects in the perspective of possible industrial applications. In conclusion, the most promising way for improving the quality of dried fruit and vegetable products is hybrid drying consisting of osmotic dehydration in concentrated fruit juices followed by heat pump drying and vacuum-microwave finish drying.


Asunto(s)
Desecación/métodos , Frutas/química , Microondas , Vacio , Verduras/química , Antioxidantes/metabolismo , Color , Frutas/normas , Calor , Polifenoles/metabolismo , Control de Calidad , Verduras/normas
17.
Sci Rep ; 13(1): 16152, 2023 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-37752295

RESUMEN

In the present research, response parameters such as specific energy consumption (SEC), thermal efficiency (TE), energy efficiency (EF), drying time (DT), greenhouse gas (GHG) emission (such as CO2 and NOx), and quality features (color variation and shrinkage) were modeled by response surface methodology (RSM) for apple slices dried in a microwave dryer under ultrasonication (30 â„ƒ-10 min) and blanching (80 °C-2 min) pretreatments. Also, RSM was applied to optimize two independent parameters including microwave power and sample thickness in the levels 100, 200, and 300 W and 2, 4, and 6 mm, respectively. The results indicated the significant influence (P < 0.01) of the independent parameters on the response parameters. The vales of SEC, DT, GHG emission, shrinkage, and color difference were linearly decreased with the declining sample thickness and increasing microwave power, while the energy and thermal efficiencies were increased by a quadratic equation. The use of ultrasonication and blanching pretreatments decreased the SEC, GHG emissions, and DT; while improving the quality of the samples as compared to the non-treated slices. The optimization results showed the optimal drying times (31.55, 82.19, and 50.55 min), SEC (3.42, 10.07, and 4.37 MJ/kg), CO2 with natural gas (1539.75, 1518.75, and 4585 g), CO2 with gas oil (3662.53, 2099.25, 2721.25 g), NOx with natural gas (10.094, 9.956, and 12.906 g), and NOx with gas oil (12.934, 12.758, and 16.538 g) at a microwave power of 300 W and sample thickness of 2 mm with desirability of 0.921, 0.935, and 0.916 for control samples, ultrasonicated, and blanched, respectively.

18.
Food Sci Nutr ; 11(5): 2166-2175, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37181321

RESUMEN

Visible-near-infrared spectroscopy is known for its rapid and nondestructive characteristics designed to predict leaf chlorophyll content (LCC) of winter wheat. It is believed that the nonlinear technique is preferable to the linear method. The canopy reflectance was applied to generate the LCC prediction model. To accomplish such an objective, artificial neural networks (ANN), along with partial least squares regression (PLSR), nonlinear, and linear evaluation methods have been employed and evaluated to predict wheat LCC. The wheat leaves reflectance spectra were initially preprocessed using Savitzky-Golay smoothing, differentiation (first derivative), SNV (Standard Normal Variate), MSC (Multiplicative Scatter Correction), and their combinations. Afterward, a model for LCC using the reflectance spectra was developed by means of the PLS and ANN. The vis/NIR spectroscopy samples at the 350-1400 nm wavelength were preprocessed using S. Golay smoothing, D1, SNV, and MSC. The preprocessing with SNV-S.G, followed by PLS and ANN modeling, was able to achieve the most accurate prediction, with the correlation coefficient of 0.92 and 0.97, along with the root mean square error of 0.9131 and 0.7305 receptivity. The experimental findings also revealed that the suggested method utilizing the PLS and ANN model with SNV-S. G preprocessing was practically feasible to estimate the chlorophyll content of a particular winter wheat leaf area according to the visible and near-infrared spectroscopy sensors, achieving improved precision and accuracy. The nonlinear technique was proposed as a more refined technique for LCC estimating.

19.
Foods ; 12(18)2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37761146

RESUMEN

Freeze-drying is an excellent method for dehydration due to its benefits, including increased shelf-life, unique texture, and, in particular, good nutritive quality. However, the applicability of traditional freeze-drying systems in the food industry is still challenging owing to their prolonged drying duration, extraordinary energy usage, and high process cost. Therefore, the need to upgrade or develop conventional freeze-dryers for common or sophisticated food structures is ever-increasing. Enhancements to the freeze-drying process can significantly speed up drying and reduce energy consumption while maintaining phytochemicals, physical quality, and sensory attributes in final products. To overcome the downsides of conventional freeze-drying, hybrid freeze-drying methods were introduced with a great potential to provide food products at shorter drying durations, lower costs, and environmental friendliness while resulting in the same nutritive and sensory qualities as that of conventional freeze-drying in special circumstances. An overview of the most current improvements, adaptations, and applications of hybrid freeze-drying in food dehydration is given here. In this review, comparative studies are offered to characterize the drying process from the standpoint of chemical quality and sensory attributes. All the reviewed studies confirmed that the nutritional and sensory qualities of the end product can be retained using hybrid freeze-drying almost to the same extent as using single freeze-drying. It was also inferred that hybrid freeze-drying can surpass conventional freeze-drying and allow for obtaining dried products with characteristics typical of raw material if operating parameters are optimized based on product quality and energy usage.

20.
Food Chem ; 397: 133802, 2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-35914462

RESUMEN

In light of large scale production of Salvia officinalis L. and its complex storage and delivery chain, the efficient preservation process is required. At this moment, the most popular preservation method is drying, therefore a comprehensive experiment to evaluate the influence of multiple drying techniques on sage was conducted. Convective drying at 40, 50 and 60 °C, vacuum-microwave drying with powers 240, 360 and 480 W and combined drying consisting of convective pre-drying at 50 °C followed by vacuum-microwave finish-drying with power 360 W were applied. To evaluate the effect of particular procedures chemical analyses were performed, namely evaluation of changes in bioactive volatile constituents, odour-active compounds and various groups of non-volatile bioactive constituents of sage. The obtained results shown, that to receive the product with expected quality, it is necessary to identify the designation of the product before treatment, since particular groups of phytochemicals react differently during drying.


Asunto(s)
Salvia officinalis , Cromatografía Liquida , Cromatografía de Gases y Espectrometría de Masas , Microextracción en Fase Sólida , Espectrometría de Masas en Tándem
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