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A non-invasive capacitance instrument was embedded in the base of a vacuum-drying tray to monitor continuously the residual amount of solvent left in a pharmaceutical powder. Proof of concept was validated with Microcrystalline Cellulose laced with water, as well as water/acetone mixtures absorbed in a spray-dried Copovidone powder. To illustrate the role of impermeability of the base, we derive a model of vapor sorption that reveals the existence of a kinetic limit when solids are thinly spread, and a diffusion limit with greatly diminished effective diffusivity at large powder thickness. By monitoring the residual solvent content of powders, this new in situ technique offers advantages over indirect methods like mass spectrometry of vapor effluents, but without complications associated with probe fouling. To prescribe design guidelines and interpret signals, we model the electric field shed by the probe when a powder holds variable solvent mass fraction in the vertical direction. [ABSTRACT FROM AUTHOR]

Holy basil (Ocimum Tenuiflorum L.) contains several bioactive compounds useful to the pharmaceutical and food industries. Microwave drying (MD) is a powerful technique for rapid drying of food or plant materials while preserving bioactive compounds during the process. However, little is known about the optimal combination of MD power with hot air drying (HAD) that can preserve the quality and yet only consume reasonable energy when drying holy basils. For that purpose, the effects of drying methods using MD combined with HAD at 45°C were examined to prevent losses in quality, antioxidant activities, and volatile flavor compounds in two holy basil cultivars (green and red cultivars). Holy basil leaves were dried at different MD powers of 200, 400, and 600  W combined with HAD and compared with a traditional tray drying (TD) at 45°C. Drying using MD at 600  W with HAD displayed significantly high levels of color retention, chlorophyll, and carotenoid content in both cultivars. The green cultivar showed a greater accumulation of total phenolic compounds (TPC), terpenoids, and DPPH free radical scavenging at 400  W with HAD. However, the red cultivar had the highest TPC, flavonoid, and terpenoid content at 600  W with HAD. The accumulation of major volatile organic compounds (VOCs) was also affected, and treatment at 600  W exhibited the highest methyl eugenol and β-caryophyllene content in both cultivars. The use of the highest power of MD (600  W) with HAD for leaf drying reduced the effective drying time and energy consumption among both cultivars. Taking into consideration the dried quality of antioxidant accumulation and energy consumed for drying, we recommend using MD at 400 or 600  W with HAD for the green cultivar and 600  W for the red. [ABSTRACT FROM AUTHOR]

Holy basil (Ocimum Tenuiflorum L.) contains several bioactive compounds useful to the pharmaceutical and food industries. Microwave drying (MD) is a powerful technique for rapid drying of food or plant materials while preserving bioactive compounds during the process. However, little is known about the optimal combination of MD power with hot air drying (HAD) that can preserve the quality and yet only consume reasonable energy when drying holy basils. For that purpose, the effects of drying methods using MD combined with HAD at 45°C were examined to prevent losses in quality, antioxidant activities, and volatile flavor compounds in two holy basil cultivars (green and red cultivars). Holy basil leaves were dried at different MD powers of 200, 400, and 600 W combined with HAD and compared with a traditional tray drying (TD) at 45°C. Drying using MD at 600 W with HAD displayed significantly high levels of color retention, chlorophyll, and carotenoid content in both cultivars. The green cultivar showed a greater accumulation of total phenolic compounds (TPC), terpenoids, and DPPH free radical scavenging at 400 W with HAD. However, the red cultivar had the highest TPC, flavonoid, and terpenoid content at 600 W with HAD. The accumulation of major volatile organic compounds (VOCs) was also affected, and treatment at 600 W exhibited the highest methyl eugenol and β-caryophyllene content in both cultivars. The use of the highest power of MD (600 W) with HAD for leaf drying reduced the effective drying time and energy consumption among both cultivars. Taking into consideration the dried quality of antioxidant accumulation and energy consumed for drying, we recommend using MD at 400 or 600 W with HAD for the green cultivar and 600 W for the red.

This paper aims to study the effectiveness of variables on process development and stability study under atmospheric condition for freezedried (FD) and tray-dried (TD) osmotically dehydrated (OD) amla (Emblica officinalis) with spices. Amla pieces were soaked in brine containing fenugreek powder, cumin seed powder, and fresh ginger extracts for OD process. Then, amla samples were FD at -50 °C for 13 h under 10-3 mbar pressure and TD at 50 °C±3°C for 13 h. Multiple regression models were developed for biochemical and microbial parameters of amla. FD and TD samples were packed in 0.05mm thickness low-density polyethylene pouches and stored at 35 °C±3°C temperature for 60 days. The moisture content of the sample increases slightly with higher regression coefficient for FD (0.046) sample than TD (0.038) sample. The regression models established positive correlation with acidity of TD and FD samples with coefficient 0.004 and 0.005, respectively. It also indicated that 0.002 increase in pH reduces the shelf life of the products. Ascorbic acid and tannin content of the dried samples followed negative nonlinear trend. The paired t test showed no significant difference (p≤0.05) between TD and FD amla pieces during the study period. [ABSTRACT FROM AUTHOR]

Musa paradisiaca (ripe Nendran) is the staple food of south India, especially Kerala. The present study analyzed the effect of different drying techniques, namely, freeze, spray and tray drying on the retention of nutrients especially micronutrients. Mineral content was determined by using Atomic absorption spectroscopy and Vitamin content was determined through High-performance liquid chromatography. This study aimed to analyze the availability of minerals and water-soluble vitamins in dried ripe banana powder. The micronutrient content of freeze-dried banana powder was observed to be with 486.92 ± 0.12 mg/100 g of potassium, 0.60 ± 0.005 mg/100 g of calcium, 3.10 ± 0.10 mg/100 g of sodium, 3.82 ± 0.02 mg/100 g of iron, 6.28 ± 0.04 mg/100 g of vitamin C and 0.606 ± 0.005 mg/100 g of vitamin B6. Along with micronutrient analysis, proximate, and various important physiochemical properties were also analyzed. The results showed that freeze-drying was the best technique to preserve nutrients present in ripe banana. Structure analysis of dried banana was done using scanning electron microscopy indicated that remarkable changes has occurred in both tray and spray dried banana when comparing to freeze dried banana. Data was analyzed by one-way ANOVA, found significantly differ at p < 0.05 with respect to drying methods. [ABSTRACT FROM AUTHOR]

Aim: The goal of this study is to evaluate the cutting force and texture of muskmelon samples using the oven and tray drying method. Materials And Methods: Group 1 (N=20) is assigned to Tray drying, while group 2 (N=20) is assigned to oven drying in this experiment. Samples of muskmelon fruits were dried in the tray and oven drier for 5, 6, and 7 hours at 40°C, 50°C, and 60°C with dimensions of 1 cm3, 8 cm³, 27 cm³ respectively. On dried materials, the cutting force (N) was evaluated using the texture analyser. The significant value was obtained at a p<0.05 level using SPSS v. 26 software. Results: When comparing the tray dry method (108 N) to the oven dry method (106 N), the oven dry method had a greater mean value of cutting force, but the tray dryer retained texture and quality. The cutting force measured from the tray and oven dried processes indicated a significant difference with a p=<0.01 (p<0.05) which is statistically significant. The size for each gathering was determined by utilizing past concentrate on outcome in clinical.com by keeping G power as 80%, edge 0.05 and certainty span as 95%. Conclusion: According to the findings, muskmelon dried at 40°C in an oven dryer has greater cutting force than muskmelon dried in a colour dryer, but tray dryer maintains adequate texture, quality, and colour, therefore tray dryer is deemed superior to the oven dryer. [ABSTRACT FROM AUTHOR]

This article targets the optimal process–product characteristics of periodic airflow assisted tray dried Kaskal (Musa splendida) and Posola (Musa balbisiana Colla pseudo-stem). Both trial and error and statistical design approaches have been considered to compare and contrast optimal process parametric and response variable characteristics of the mentioned dried vegetable samples. Based on the carried investigations, optimal process and response variable data were achieved for the statistical design-based approach. Drying kinetics studies affirmed moisture diffusivities to vary from 1.56 × 10–11–7.59 × 10–11 m2 s−1 and 1.79 × 10–11–7.35 × 10–11 m2 s−1 for Kaskal and Posola, respectively. For the Kaskal vegetable system, the RSM-based optimal tray drying process and response variables correspond to 58.66 °C, 400.31 min, 5.09%, 80.73 mg (100 g)−1 and 72.34% for drying temperature, drying time, moisture content, vitamin C content and antioxidant activity for Kaskal. Corresponding values for the tray dried Posola refer to 57.59 °C, 389.42 min., 2.84%, 53.38 mg (100 g)−1 and 25.72%. [ABSTRACT FROM AUTHOR]

Edible crickets have gained attention as a promising high-protein food source. However, the understanding of how different drying methods affect the allergenic properties of cricket-derived proteins remains limited. In this study, we aimed to assess the effect of two distinct drying methods, microwave vacuum drying and tray drying, on the allergenicity of proteins found in G. bimaculatus , also known as the two-spotted cricket. Employing immunoblotting and indirect enzyme-linked immunosorbent assays (ELISA), we investigated potential alterations in allergenicity following heat treatment, with the allergenic proteins subsequently identified using liquid chromatography tandem mass spectrometry (LC-MS/MS). Our findings revealed that nine protein bands were recognized by IgE of allergic volunteers and three proteins were identified, which were tropomyosin, actin, and hexamerin-like protein 2. The alteration on the allergenicity of the heat-labile allergens was more pronounced in tray drying method. This work provided valuable insights into the food safety aspects of consuming edible insects. • Microwave vacuum drying and tray influence allergenicity of protein allergen. • Drying method variably affects heat-labile allergens. • Insights into food safety of consuming processed edible insects. [ABSTRACT FROM AUTHOR]

Benefits of beta (β)-carotene are well known, most important being the pro vitamin A activity but experimental evidence are lacking regarding the effect of processing on β-carotene. Processing is critical in determining the bioavailability of β-carotene from foods and there is a perception that β-carotene is destroyed by the heat process involved in cooking of vegetables. This study is intended to determine the stability of β-carotene when selected vegetables are subjected to various processing techniques. Carrot and spinach were chosen for this study since they are the two most important sources. β-Carotene was quantified from vegetables by Reversed phased High Performance Liquid Chromatography (HPLC) System. The result indicated the control sample reading of carrot and spinach were 16833µg/100g and 19383µg/100g, the β-carotene level increased substantially in all the processing conditions. Tray drying proved to be the best processing technique with highest percentage gain. Among the samples, Spinach was found to be the richest source of β-carotene. [ABSTRACT FROM AUTHOR]

Musa balbisiana Colla blossom has enriched applications as a key constituent of dried vegetable formulations. With restricted prior art, the article addresses the optimality of tray drying characteristics of the blossom from both statistical design and drying kinetics perspective. The process variables in due course of optimization refer to moisture content, antioxidant activity and vitamin C for variation in drying time and temperature. Model fitness, analysis of variance based analysis and numerical optimization were considered during the statistical design of experiments. Drying kinetics involved fitness studies of alternate models, moisture diffusivity and process variable characteristics. Thereby, the sensitivity of both approaches to obtain optimal parameters associated with tray dried product have been targeted for a comparative assessment. [ABSTRACT FROM AUTHOR]

Broccoli offers several health benefits due to its high content of bioactive compounds, especially sulforaphane – a promising anticancer compound. In Chile, the broccoli crop is expanding rapidly, creating opportunities to industrialize this vegetable and exploit its functional properties. Various processes have been studied with the aim of maximizing the sulforaphane content in processed broccoli using different dehydration methods. These have shown large differences in terms of recovery and cost. This work shows an economic feasibility study of a small‐scale plant for the production of sulforaphane‐rich broccoli flour considering three drying alternatives: tray drying (TD), pulsed fluidized‐bed drying, and freeze‐drying (FD). Freeze drying resulted in the highest sulforaphane content in the broccoli flour; however, this process entails the highest production cost. Tray drying showed the lowest production cost and a comparatively high sulforaphane content in the final product. Pulsed fluidized bed drying (PFBD) resulted in the highest sulforaphane loss. Although the three drying technologies resulted in positive net present values (NPV), the internal rate of return (IRR) was the lowest for freeze drying as a result of the high investment – over 20% higher than the investment required by the other alternatives. The NPV was practically independent of the drying technology when the sulforaphane content was considered in the estimation of the selling price. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Mushrooms are health foods due to their nutritional values and antioxidant properties. This study investigated chemical properties, total phenolic content (TPC), antioxidant activities (2, 2-diphenyl-1-picrylhydrazyl; DPPH and 2, 2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid); ABTS) and selected phenolic acids from five different tray-dried and freeze-dried mushrooms (Pleurotus ostreatus, Pleurotus pulmonarius, Schizophyllum commune, Volvariella volvacea and Lentinus edodes). The extracts were prepared using methanol and hot water extractions. The results revealed that V. volvacea had the highest protein (28.70%) and ash (9.48%) contents. There were significant differences among some tray dried and freeze dried mushrooms regarding TPC, DPPH and ABTS. However, tray drying tended to improve TPC, DPPH and ABTS in P. ostreatus, P. pulmonarius and L. edodes. Among five mushroom species, both methanol and hot water extractions of V. volvacea had the highest TPC, DPPH and ABTS values but there were no significant differences between mushrooms prepared using tray drying and freeze drying. Moreover, the yield and contents of gallic acid and p-hydroxybenzoic acid from the hot water extracts were higher than from the methanol extracts. Therefore, tray-dried V. volvacea had the most potential as a natural antioxidant and could be used as a functional ingredient in healthy food products. [ABSTRACT FROM AUTHOR]

This research was carried out to investigate the four different drying methods i.e., shade, sun, oven and tray drying on the proximate composition and some minerals of Moringa oleifera. The proximate analysis and some minerals were analyzed using standard analytical procedures. The study revealed that the tray drying method was observed suitable for dehydration of drumstick leaves. The results revealed that four different drying methods varied from 4.26 to 6.30 per cent, 19.86 to 25.42 g, 2.79 to 4.44g, 10.17 to 14.90g, 7.60 to 9.80g, 41.18 to 53.28g, 306 to 317 Kcal, 20.03 to 26.17mg, 86.03 to 168.30mg, 27597 to 35488.53 µg/100g for moisture, protein, fat, crude fibre, ash, carbohydrate, energy, iron, vitamin C and β - carotene. The study revealed that in tray drying method the retention of nutrients is more when compare to other processing methods and suitable for dehydration of Moringa oleifera. [ABSTRACT FROM AUTHOR]

The study describes the influence of precooking on drying kinetics of taro slices and quality of resulted flour. The precooked slices in different medium required lesser drying time as compared to uncooked slices. Precooking time had the significant reduction in drying time of slices to achieve desired final moisture content. Seven thin layer drying models were selected to describe the drying behavior of precooked taro slices. On the basis of highest R 2 , lowest χ 2 and RMSE value, Logarithmic model was the most appropriate to describe the drying behavior of precooked taro slices. The effective moisture diffusivity of precooked taro slices was found in the range 3.55×10 −9 to 6.84×10 −9 m 2 /s. The flour from taro slices, cooked in lemon solution had lowest antinutritional factors and better color but comparatively inferior functional properties. By considering overall quality of flour, water cooked slices flour samples was the best. [ABSTRACT FROM AUTHOR]

Basil is a popular aromatic and annual herb growing in many regions of the world. Immediately after its harvesting, the highly perishable raw material, i.e. leaves, have to be preserved against deterioration and spoilage. More often, during peak period, most of the crop is lost/wasted due to lack of proper post-harvest processing techniques. Drying is by far the most widely used treatment, which needs to be performed very carefully and preciously so as to preserve the aroma and color of the leaves. Various drying treatments and experimental methods viz., solar drying, tray drying, vacuum drying and fluidized bed drying were carried out at the temperatures of 45°C, 55°C and 65°C to find and suggest the optimum drying condition for acquiring quality dried basil leaves. Results have revealed that 'total drying time' is considerably reduced with the increase in drying air temperatures from 45°C to 65°C. It could be recommended that for the best drying of basil leaves, the drying operation needs to be carried out in the fluidized bed dryer at 45ºC for 30 s steam blanched sample ensuring the best results in quality of basil leaves as compared to other methods and treatments whatever considered during present study. [ABSTRACT FROM AUTHOR]

Sulforaphane is a natural anticancer compound found in broccoli that comes from hydrolysis of glucoraphanin. Conversion of glucoraphanin to sulforaphane has been optimized, however, its use as functional ingredient is limited because sulforaphane is thermo-labile. We investigated the effect of drying air temperature (60, 70, 80 °C) in tray drying of sulforaphane-enriched broccoli on the evolution of sulforaphane content. Broccoli temperature and sulforaphane content were registered in time. Sulforaphane content profiles were adjusted to a first-order kinetic model, showing acceptable agreement (r > 0.90). Sulforaphane formation occurred below 40 °C; formation and degradation occurred at broccoli temperature above 40 °C, until the low content of glucoraphanin and moisture, prevents reaction. After that, only sulforaphane degradation was detected. The highest sulforaphane content at X/X 0 = 0.1 was 67.6 mg/100 g DW, obtained with drying air temperature of 70 °C, being 4-fold higher than that found in fresh broccoli, and the highest reported so far in any dehydrated food. [ABSTRACT FROM AUTHOR]

Gac fruit (Momordica cochinchinensis L.) pulp is high in carotenoids and fiber; however, it is discarded during process. Both maturity stages of matured gac fruit could be used in the drying experiments. Gac fruit pulp was dried by different drying methods including tray drying (40-60 °C), heat pump-assisted dehumidified drying (40-60 °C), microwave drying (450-900W), mixed-mode solar drying and freeze drying. The Modified Henderson model presented the best fit of desorption isotherms. New model proposed was the best drying model. Quality evaluation by β-carotene, lycopene, lutein, total phenolics and antioxidant activity revealed that heat pump-assisted dehumidified drying at 60 °C provided the highest lutein, total phenolics and antioxidant activity and could reduce drying time by 25% and increased lutein, total phenolics and antioxidant activity by 12.6%, 32.0% and 0.3%, respectively and is more promising drying method for gac fruit pulp. [ABSTRACT FROM AUTHOR]

Jambhul and wood apple were subjected to two different drying methods to examine the effect of drying temperatures (80 °C and 60 °C) and influence of storage conditions viz., room temperature (25 °C) and refrigeration temperature (4 °C) on bioactive constituents of jambhul and wood apple powder for 90 days. Results showed that retention of phenolics, ascorbic acid and antioxidant capacity such as ABTS, DPPH and FRAP in jambhul and wood apple were high at 80 °C as compared to 60 °C in both tray and IR drying. Anthocyanin and flavonoid significantly ( p < 0.05) decreased at 80 °C. Jambhul showed retention of 30.83 % TPC, 10.40 % TFC, 9.31 %, TMAC, 12.75 % ascorbic acid, 19.26 % ABTS activity, 98.71 % DPPH activity, and 27.78 % FRAP activitys in IR drying; whereas wood apple showed more retention of 25.74 % TPC, 61 % ascorbic acid, 10.31 % ABTS, 36.45 % DPPH and 0.27 % FRAP in tray drying (TD). During storage bioactive constituents in jambhul powder were preserved at refrigeration temperatures whereas in wood apple they were retained at room temperature. [ABSTRACT FROM AUTHOR]

The most appropriate maturity stage ofMoringa oleiferaleaves was selected for drying based on phytochemical content, including quercetin and kaempferol. Desorption isotherms were developed and were best fit by the modified Henderson model. Prior to drying, samples were left untreated, blanched in boiling water, and blanched in NaHCO3/MgO. The leaves were dried by hot air tray drying (TD) and heat pump–dehumidified drying air (HPD) at air temperatures of 40, 50, and 60°C. Alternatively, leaves were subject to microwave drying (MWD) at 150, 450, and 900 W and to freeze drying (FD). The moisture versus time data were fitted to five drying models. In general, a three-parameter model gave the best fit. The drying constant was related to the drying temperature or microwave power using an Arrhenius model. Effective moisture diffusivity (Deff) increased with higher drying temperature, higher microwave power, or blanching treatments. Structural changes in the leaves after drying and upon rehydration were observed by scanning electron microscopy (SEM). Leaves blanched and dried using HPD at 50°C and fresh and dried using FD showed a partial breakdown of the tissue structure upon rehydration. HPD and blanching reduced the drying time by 8.3% and increased quercetin and kaempferol levels by 42.1 and 51.4%, respectively, compared to TD at 50°C. MWD provided the quickest drying followed by HPD and TD, respectively. HPD drying ofM. oleiferaafter blanching resulted in relatively greater quality compared to TD and MWD. [ABSTRACT FROM PUBLISHER]

The appropriate stage of maturity of Centella asiatica (L.) Urban leaves was investigated. Mature leaves with large diameter contained high total phenolics and % inhibition. Microwave blanching for 30 s retained the highest total phenolics and the microwave blanching for 30 s and 45 s retained the highest % inhibition. Modified Henderson and Modified Chung-Pfost models showed the best fit to both fresh and blanched leaves for equilibrium moisture content, X = f(RH, T) and equilibrium relative humidity, RH = f(X, T), respectively. The Modified Page model was the most effective model in describing the leaf drying. All drying was in the falling rate period. The drying constant was related to drying air temperature using the Arrhenius model. Effective moisture diffusivities increased with increasing temperature and blanching treatments as well as dehumidification by heat pump-assisted dehumidified dryer. The heat pump-assited dehumidified drying incorporated by the microwave blanching could reduce the drying time at 40 °C by 31.2 % and increase % inhibition by 6.1 %. Quality evaluation by total phenolics, % inhibition and rehydration ratio showed the best quality for C. asiatica leaves pretreated by microwave blanching and dried at 40 °C in heat pump-assisted dehumidified dryer. [ABSTRACT FROM AUTHOR]

Corchorus olitorius , known as molokhia, is a good source of protein, which makes it a cheap and high quality food material. Molokhia could be dried to obtain a new functional food ingredient. In this study, molokhia powders dried by different methods (oven, tray, microwave and vacuum drying) were used in erişte with 2.5, 5, 7.5 and 10% substitution ratios. Physical, chemical, sensory properties and cooking quality of erişte samples were investigated. Molokhia powder substitution led to an increase in the ash, crude fat and protein contents of erişte samples. Substitution ratio of 2.5% provided higher quality on the color, firmness and cooking quality properties. As the substitution ratio increased from 0% to 10%, the total polyphenolic content of erişte samples increased from 100.26 mg GAE/kg to 245.68 mg GAE/kg. Similarly, the DPPH radical scavenging activity of samples increased from 10.05% to 76.92%. Microwave drying has provided better color values and higher ash, crude fat and crude protein contents in erişte. Consequently, the nutritional properties of a traditional type of product, erişte was improved with molokhia powder substitution. Microwave drying was successfully applied to obtain high quality molokhia powders. [ABSTRACT FROM AUTHOR]

Papad is familiarly known as an Indian food adjunct or snack food. In this study, attempts have been made to increase the protein, minerals and crude fibre content of the papad with incorporation of Pleurotus sajor-caju powder to develop a novel snack food. Mushroom powder was added in different proportions with other ingredients of the papad and the prepared papad was subjected to physicochemical and sensorial analyses. Mushrooms pretreated with 1% potassium metabisulphite followed by whey treatment had better colour and reduced drying time. Drying at 50°C produced more amount of mushroom powder (350 μ) and had higher acceptability of rehydrated samples. The papad enriched with 20% mushroom powder showed increased values of protein (15.8%), minerals (38.87%) and crude fibre (218.18%) content and had maximum sensory score. Therefore, papad supplemented with oyster mushroom powder may help to reduce protein malnutrition, constipation and mineral deficiency disorders. [ABSTRACT FROM AUTHOR]

Desorption isotherms for sliced gingers have been measured. A non-linear regression programme was used to fit four moisture sorption isotherm models to the experimental data. The Modified Halsey and Modified Oswin models gave the best fit for Xe= f(RHe, 7) and RHe f(Xe, T), respectively. Tray and heat pump dehumidified drying incorporated by single and two stage drying were conducted. It was found that the modified Page model was the most effective. The drying constant was fitted to drying air temperature using the Arrhenius model. Effective moisture diffusivities were determined using the drying data. The heat pump dehumidified drying incorporated by the two stage drying could reduce the drying time at 40°C by 59.32% and increase 6-gingerol content by 6%. Quality evaluation by 6-gingerol content, rehydration ratio and ΔE° showed the best quality for dried sliced gingers in the heat pump dehumidified drying incorporated by the two stage drying at 40 °C. [ABSTRACT FROM AUTHOR]

The maturity of ivy gourd leaves was based on total chlorophyll and chlorophyll a. Desorption isotherms for fresh and blanched ivy gourd leaves have been measured. A nonlinear regression program was applied to the experimental data to fit with any of the four moisture sorption isotherm models. The modified Henderson model gave the best fit. Ivy gourd leaves were pretreated by different blanching methods prior to drying under three temperatures of 50, 55 and 60°C in tray and heat pump-dehumidified dryer. The drying data were fitted to the modified Page model. The drying constant was related to air temperature using an Arrhenius model. Effective moisture diffusivities were determined using the drying data. The degradation of total chlorophyll followed first-order kinetics. Heat pump-dehumidified drying and blanching methods reduced drying times. Quality evaluation showed best quality for ivy gourd leaves pretreated by blanching with chemicals and dried at 50°C in a heat pump-dehumidified dryer. [ABSTRACT FROM AUTHOR]

Desorption isotherms of mature kaffir lime leaves are determined and a nonlinear regression program was applied to the experimental data to fit with any of the four moisture sorption isotherm models. It was found that the modified Halsey model could fit the best. Tray and heat pump-dehumidified drying of kaffir lime leaves were conducted and it was found that the modified Page model was the most effective one. The drying constant was fitted to drying air temperature using the Arrhenius model. Effective moisture diffusivities were determined using the drying data. Heat pump-dehumidified drying reduced drying time and provided dried kaffir lime leaves with higher amount of citronellal than tray drying. [ABSTRACT FROM AUTHOR]

Abstract: The tray drying of cellulosic fibres from citrus fruits has been studied here, for hot air drying at dry-bulb temperatures from 40–80°C, a wet-bulb temperature of 40°C, and a cross-stream air velocity of 1.3ms−1. It appears that a single characteristic drying curve may be adequate to describe the drying behaviour of the fibres, whether the fibres are mixed with water or with hibiscus extract. The amount of hindrance to moisture movement seems to be small relative to many other materials, and the characteristic curve has the approximate form f = Φ 0.5. Comparison of the characteristic curve with the normalized drying rates measured by previous workers suggests that the characteristic curve remains applicable for sugar beet fibres dried in hot air over a wider range of temperatures, from 130 to 183°C. The importance of the basic cellulosic component in the fibres in controlling the drying behaviour may explain the absence of any significant difference between the normalised drying rates for sugar beet fibres and those for citrus fibres. In the context of drying the fibres by other methods, including spray drying, compared with the tray drying used here, the absence of substantial additional hindrance to the movement of moisture caused by the extract (compared with water) may be useful. [Copyright &y& Elsevier]

The drying kinetics of olive cake, the solid by-product of the olive oil extraction process, has been experimentally investigated in a small-scale tray dryer using both constant and intermittent (on/off) heating schemes. The parameters investigated include inlet air temperature and intermittency of heat input. The drying kinetics was interpreted through two mathematical models, the Page equation and the Lewis equation. The Page equation was most appropriate in describing the drying behavior of olive cake. A diffusion model was used to describe the moisture transfer and the effective diffusion coefficient at each temperature was determined. The dependence of the effective diffusion coefficient on drying temperature can be adequately explained based on an Arrhenius-type relation. The effective diffusion coefficient varied between 7.6 × 10-8 and 2.5 × 10-7 m2/min with an activation energy of 38.55 kJ/mol. Comparison of time evolution of material moisture content due to intermittent and constant drying is also made. [ABSTRACT FROM AUTHOR]

Effect of varying drying air temperature, air velocity, initial total solids, and starch addition on the drying rate of tomato paste were studied using a tray dryer. The increase in the inlet air temperature in the range 60–100°C markedly increased tomato paste drying rate. Also, increasing air velocity (0.8–1.2 m/s) increased the drying rate of tomato paste. Increasing tomato paste initial total solids had a significant effect on the time required to reach the equilibrium moisture content. Starch was added at different amounts (0.0–1.0 kg dry starch/ kg dried tomato paste); it has a significant effect on tomato paste drying rate. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the effects of different drying methods on the physical properties, total phenolic content, total flavonoid content, and antioxidant activity of extracts from Moringa oliefera L. (MO) leaf waste. The effects of two drying techniques, namely, sun drying (A1) and tray drying (A2), on the physical and antioxidant properties of the extracts obtained using three extracting solvents, i.e., water (b1), ethanol (b2), and ethyl acetate (b3), were investigated. These extracts were analyzed for their physicochemical and antioxidant properties. The antioxidant properties were determined with the Folin Ciocalteau, aluminum chloride, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays. Fourier transform infrared spectrophotometry (FTIR) was used to identify functional groups in the active compounds. It was found that the physical properties of the MO extract, including yield, pH, total solids, and color, showed significant differences for the two drying methods (p < 0.05). The b3 extract had the highest value for total phenolic contents, total flavonoid contents, and antioxidant activities, followed by b2 and b1, respectively, for both the sun drying and tray drying methods. There was a significant correlation between the total phenolic and flavonoid contents and antioxidant activity (IC50). This study reveals that waste material from MO leaves could be utilized as an antioxidant agent, which is expected to reduce environmental pollution from the MO processing industry. [ABSTRACT FROM AUTHOR]

Given a sizable proportion of bio-resource production in the North-east (NE) India and the need to enhance the shelf life of perishable horticultural regional produce, this work addresses the optimality of inexpensive oven and intermittent airflow assisted tray drying processes for Kolmou ( Ipomoea aquatica Forssk.), Pui ( Basella alba ), Jatialao sak ( Lagenaria siceraria leaves), Kolphul ( Musa balbisiana Colla blossom), Kaskal ( Musa splendida), green Komora ( Benincasa hispida ) and Posola ( Musa balbisiana Colla pseudostem) vegetables of NE India. Characterization parameters for process parametric optimality include proximate analysis based evaluation of moisture content, yield, carbohydrate, crude protein, soluble protein, vitamin C, antioxidant activity, ash, crude fibre and fat content. For most vegetables, tray drying process performance is superior in terms of better moisture removal, higher yield and higher anti-oxidant activity. Among all considered samples, tray dried Kolmou possessed highest antioxidant activity. Vitamin C content was seen to be highest in tray dried Komora., (© 2019 Published by Elsevier Ltd.)