Developing a sustainable photovoltaic-thermal (PVT) solar drying system is essential to maintain zero carbon emission in the drying process. This work represents the drying of star fruit in a novel ...PVT solar dryer to analyze the sustainability indicators based on the energy and exergy performance with the environmental and economic evaluation (4E) under forced convection drying (FCD) and natural convection drying (NCD). The moisture content of star fruit in the PVT solar dryer is decreased from 10.11 (d b) to 0.19 (d b.) in 12.50 h and 14.50 h under FCD and NCD, respectively. The same has been obtained in open sun conditions with a drying time of 22.00 h. The PVT energy and exergy efficiencies are 69.27% and 31.12% in FCD mode, respectively, and 43.58% and 17.89% in NCD mode. The drying efficiency of 15.27% and 13.98%, specific moisture extraction rate of 0.1786 kg/kWh and 0.6657 kg/kWh, and specific energy consumption of 12.37 kWh/kg and 3.57 kWh/kg are evaluated in FCD and NCD modes, respectively. The drying system payback time is 1.40 yr and 1.70 yr in FCD and NCD mode, respectively.
Review of drying technology of fig Mat Desa, Wan Nurlaila; Mohammad, Masita; Fudholi, Ahmad
Trends in Food Science & Technology,
June 2019, 2019-06-00, 20190601, Letnik:
88
Journal Article
Recenzirano
Ficus Carica L., or more commonly known as figs, is one of the first cultivated fruits in human history that is consumed worldwide today. As one of the apparent efforts to increase its production to ...meet the market demand, it is important to reduce wastage by preventing post-harvest losses. These wastages can be eliminated by ensuring harvested crops receive proper preservation techniques that is accessible and available, especially in rural areas. Solar thermal application offers numerous potentials as agricultural preservation techniques, regardless of geographical and technological challenges. Drying has proven to be a reliable preservation method for figs, in terms of technical feasibility and nutritional quality. Across the three major drying systems; natural sun drying, artificial drying and solar assisted drying, the key parameters that determine successful drying for fig remain the same which are drying temperature and duration of drying. In contrast to the expensive, energy intensive artificial drying and unreliable, slow sun drying, solar drying is able to provide an alternative with adequate drying capacity. It has been shown that this system can be further modified and improved to achieve shorter drying time and constant heat supply, which should be the focus of future studies.
•This paper attempts to discuss on the preservation of figs using drying techniques.•This paper discusses to improve the process for product quality enhancement.•Comparisons among three major drying mechanisms; natural sun-drying, artificial drying, and solar assisted drying are presented.•Solar drying is able to provide an alternative with adequate drying capacity.
Abstract: The tocopherol contents of unripe and ripe avocado fruit oil extracted from Pinkerton, Hass and Fuerte varieties were determined after drying fruit using air, microwave or oven drying ...methods. The α-tocopherol content changed between 13.70mg/100g (microwave-dried) and 28.06mg/100g (air-dried) in oil from unripe Pinkerton fruit; between 14.86mg/100g (microwave-dried) and 88.12mg/100g (fresh) in oil from unripe Hass fruit and between 13.31mg/100g (microwave-dried) and 17.35mg/100g (oven-dried) in oil from unripe Fuerte fruit. The α-tocopherol contents in oil from ripe Fuerte fruit changed between 13.21mg/100g (fresh) and 17.61mg/100g (oven-dried). In addition, γ-tocopherol contents varied between 11.55mg/100g (air-dried) and 14.61mg/100g (microwave-dried) unripe "Pinkerton" fruit; between 11.52mg/100g (air-dried) and 15.01mg/100g (fresh) in unripe Hass fruit and between 12.17mg/100g (air-dried) and 15.27mg/100g (microwave-dried) unripe Fuerte fruit. The γ-tocopherol contents ranged from 12.71mg/100g (fresh) to 17.40mg/100g (oven-dried) in ripe Hass fruit; from 10.29mg/100g (fresh) and 17.20mg/100g (microwave-dried) ripe Fuerte fruit. α-, β-, γ- and δ-tocopherols could not be detected in ripe fresh Pinkerton fruit. In general, β- and δ-tocopherol could not be detected in most of the unripe and ripe avocado fruit oils. α-Tocopherol and γ-tocopherol contents of dried ripe Fuerte fruit oils were found to be higher compared to those of dried unripe Fuerte fruits.
Jujube cultivars have been imported into the United States for more than 100 years, but cultivar trials have been limited. To accurately recommend cultivars for each region, trials have to be ...conducted. We have set up jujube cultivar trials at the New Mexico State University (NMSU) Alcalde (2015, USDA hardiness zone 6a), Los Lunas (2015, 7a), and Leyendecker (2017, 8a) Centers with over 35 cultivars at each site with two replicates and a complete random block design. We reported the early performance of fresh-eating cultivars in 2019. Here we report the performance of 19 drying and multipurpose jujube cultivars. Between 40% and 100% of jujube trees produced a few fruit to more than 100 fruit in the planting year, depending on cultivar and location. Trees were more upright at Los Lunas than at Alcalde. ‘Kongfucui’ (KFC) was the most productive cultivar at Alcalde with 13.3 kg/tree in 2019, followed by ‘Chaoyang’, ‘Jinkuiwang’ (JKW), ‘Pitless’, and ‘Lang’. The yield at Los Lunas was lower than Alcalde for the first 3 years after planting; however, ‘Jinsi 2’, ‘Jinsi 4’, ‘Jixin’, ‘Sherwood’, ‘Sihong’, and ‘Xiangzao’ produced higher yields at Los Lunas than Alcalde in 2019. All cultivars produced higher yields and contained higher soluble solids at Leyendecker than Alcalde and Los Lunas at similar ages. ‘JKW’ was the most vigorous and productive cultivar at Leyendecker. ‘JKW’, ‘Xiangzao’, and ‘Lang’ produced more than 3.0 kg/tree in their second year after planting. ‘JKW’ yielded 12.3 kg/tree in its third year after planting. Among the three locations, drying cultivars are not recommended for commercial production at Alcalde. However, home gardeners can plant multipurpose and early-drying cultivars at Alcalde. Leyendecker produced the best dry fruit with larger fruit size, rich color, and meaty fruit; dry fruit quality was acceptable in most years at Los Lunas except 2019. We preliminarily recommend some drying and multipurpose cultivars for each location. As trees mature and produce more fruit, we will fine-tune the cultivar recommendations. We also discuss the jujube cultivar zoning information in New Mexico and fruit uses.
Kiln-dried fruit drying time is readily predicted from initial moisture content since the environment is tightly controlled. For uncontrolled environments, such as a greenhouse solar dryer, a ...product's drying time varies depending on ambient conditions and is thus more difficult to predict. Prediction of the drying time is needed to better schedule dryer use. Data was obtained from a set of wireless scales that weigh the waste during solar drying after initial moisture content measurement of a sample. A set of linear and quadratic models for drying rate are tested with the best yielding a 39% reduction in RMSE over traditional models. The results indicate that the modelling approach is likely to be useful for open solar dryers where the temperature, and thus the drying rate, is not controlled.
•Mango waste solar drying rate is affected by moisture equilibrium and temperature.•A drying rate modelling approach is proposed for varying temperature environments.•Resulting model significantly outperforms several prior models.•Data-sets for 18 drying batches provided for reproducibility.
A heat and mass transfer model has been developed to highlight, by CFD (Computational Fluid Dynamics) simulation, the moisture and temperature gradients in convective drying process of apricots. The ...drying simulation was performed for the unsteady flow regime, for unblanched and blanched apricots, by following the moisture content and the temperature from the boundary layer and pulp. The apricots were represented with a geometry that doesn't change over time, and their pulp as a homogenous and isotropic vegetable material. The dryer–apricot model discretisation was hybrid. The heat and mass transfer model was linked to the CFD simulation by UDF (User Defined Functions), using functions for the physical properties of apricots and warm air, which vary with time. The apricots were dried with warm air, using a system which allowed the monitoring and adjustment of air velocity and temperature. During the experiments the warm air parameters were as follows: air velocity of 1 m/s, air temperature of 353 K, drying time 2.5 h. The blanching of apricots was performed by immersion into water at a temperature of 363 K, for 120 s. Several data obtained by the experiment of drying process were included into CFD simulation. The final moisture and temperature results obtained by simulation and experiment were compared, with the purpose to evaluate the accuracy of the drying model, for blanched and unblanched apricots.
•The paper aimed to determine the temperature and moisture gradients in the apricots.•The gradients differ significantly in median cross section of the apricots.•The experimental results were in agreement with the results obtained by simulation.•The results showed a faster drying of the blanched apricots.
Illawarra plum (IP) is a fruit native to Australia and is a source of antioxidants including phenolics and anthocyanins which contribute important functions in food preservation and quality. However, ...the retention of natural antioxidants is influenced by thermal processing due to their sensitivity to heat. This study measured the impact of three common drying methods to identify the best processing conditions, including cost effectiveness on retaining the quality of IP. The colour (L*, a*, b*), levels of total phenolics, flavonoids, proanthocyanidins, anthocyanins and antioxidant scavenging capacity of the samples were measured on dried IP fruits (freeze dried, convection oven 70, 90, 110 °C or vacuum oven 70, 90 or 110 °C). The freeze dried sample observed the best colour (L* 44.18±0.50, a* 16.72±0.15, b* 1.66±0.04) and highest levels of compounds from the methods observed: TPC 679.19±15.04 mM GAE/g DW, TFC 190.25±4.65 mM CE/g DW, proanthocyanidins 422.46 ± 21.52 mM CE/g DW, DPPH 562.51±40.69 mM TE/g DW, monomeric anthocyanins 402.58±3.97 µg C3G/L DW and 57.97±2.84 % polymeric anthocyanins. For maximum retention of quality, freeze drying is recommended, however, it is costly and for a more economical approach, vacuum drying at 90 °C or convection oven drying at 110 °C are identified as suitable conditions for drying IP to prevent unnecessary loss of phenolic quality, however these methods will cause shrinkage and browning in the fruit. These conditions can be applied for drying IP for direct use as a dried product or for further applications in food
The aim of this work is to increase the efficiency of the fruit drying process with the SHF treatment in a uniform rectilinear movement. In order to achieve the purpose of the work, an experimental ...installation for fruit drying was developed with the application of the SHF treatment in the uniform rectilinear movement, on the basis of which the research was carried out. The efficiency of the drying process with the application of the experimental installation was estimated for 3 types of fruits: peaches, pears and apples. These types of fruit have been selected for the study because their drying is currently problematic, and they are of great interest to consumers and to processing and marketing businesses. The main results obtained regarding the application of the plant developed for fruit drying are: the drying process speed increase, the heat processing time decrease, the electricity consumption reduction, the dried fruit quality improvement and the processing costs reduction. Moreover, the installation is simple in terms of construction, low cost and easy use. At the same time, the installation allows the automation of the process, and during the research it demonstrated a high level of safety. The significance of the results obtained lies in solving a number of current problems faced by primary agri-food processing companies, by streamlining the process of drying fruit in rounds, mainly by reducing the technological processing costs and improving the quality of dried fruit for storage, marketing and use in nutrition.
Fruit drying traditions in Hungary Surányi, D.
International journal of horticultural science,
04/2017, Letnik:
23, Številka:
1-4
Journal Article
Recenzirano
Odprti dostop
Since the early eras of human history, the gathered products (roots, shoots, crops, fruits etc.), the environmental conditions of the preservation of the animals caught and the fishes; and accidental ...observations have been born new methods. Under cold and moderate climates, the effect of permanent frost, the use of ice as a means of curing as in dry, desert areas is the drying or exsiccation and the dehydration of salt. For convenience reasons, some of these methods have been forgotten, but the resurfacing of different fruits seems to resume. The short review gives an overview of the methods of drying used in the Carpathian Basin, especially among the Hungarian ethnic groups, which by the Hungarian ethnology thoroughly explored. The author attaches outstanding importance to the fruit-drying industry, because dried-ups at industrial scale are not equivalent to traditional low-fat lime scales. Excellent drying products are much better in terms of eating habits, with modern methods and small-scale production relatively easy to produce.
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