Drying Process and Technology

This research evaluated the nutritional quality of meals that were served to school children under the Ghana School Feeding Programme in Wa and Cape Coast. A cross-sectional and descriptive survey research designs were employed from which purposive and simple random sampling technique was adopted. In all, a total of 720 respondents were selected and that comprised 600 pupils, 60 teachers and 60 kitchen staff. Data were also obtained using questionnaire, observation and unstructured interview instruments. The data were then analysed with database and statistical software such as SPSS, ESHA, FNPD and USDA National Nutrient Database for Standard Reference. Qualitatively, the findings revealed that meals served in the schools had most of the needed food nutrients. However, the mean daily nutritional values intake of the pupils in the schools in both studied areas did not meet the recommended nutrient intake value. It is therefore recommended that the government should enhance the nutritional quality of the meals served to the pupils by supplying vitamin supplements. Again, the government should consult experts in food and nutrition in each region to redraw menu which has nutritional benefits from locally grown foods.

Soysal Y, M Keskin, A Arslan, YE Sekerli. 2018. Infrared Drying Characteristics of Pepper at Different Maturity Stages. International Conference on Energy Research (ENRES2018), 1-2 November 2018, Alanya, Turkey, Proceedings Book, pp.293-304. ........... ............. ........ ......... .............. ............... ............. ............. ............. ............ ............
Abstract: The influence of maturity stages on the infrared drying kinetics and moisture diffusion characteristics of pepper slices were investigated. Increasing the drying temperature decreased the drying time considerably. Compared to the green pepper samples, drying time of the red pepper slices was 1 to 7 min longer depending on the drying temperature. Entire drying process for both green and red pepper slices took place mainly in falling rate period. Among the 11 mathematical models tested to fit the moisture ratio changes during the drying of pepper slices, the Midilli et al. (2002) model gave the best fit for all data points. The value of the drying coefficient k increased with the increase in the drying temperature. Considerable increases were observed in the effective moisture diffusivity values with the increase in infrared drying temperature. Depending on the drying temperature range studied, the Deff values of the green pepper samples varied from 0.5363x10-10 to 1.1369x10-10 m2s-1 and red pepper samples from 0.6079x10-10 to 1.2561x10-10 m2s-1. The Deff values of the red pepper slices dried at 50°C and 70°C were significantly higher than those of the values for green pepper slices (P<0.001). Activation energies (Ea) were predicted as 34.69 kJ/mol for the green pepper slices and 33.46 kJ/mol for the red pepper slices. The closeness of Ea values implies that the unripe (green) pepper is as sensitive as the ripe (red) pepper to infrared drying temperature. Moreover, the ripening of the pepper from green to red did not change much of its structural properties controlling its heat transfer characteristics. The moisture content and drying rate versus drying time profiles also supports these findings. ............. ........... ............ ........... ........... ............ ............. ............. ............ ............. ............. ...............
Özet: Bu çalışmada, biberin olgunlaşma düzeyinin, biberin kızılötesi kuruma kinetiği ve nem yayılma özellikleri üzerine etkisi araştırılmıştır. Kurutma sıcaklığının arttırılması, kuruma süresini önemli ölçüde azaltmıştır. Kırmızı biber dilimlerinin kuruma süresinin, yeşil biber ile karşılaştırıldığında kuruma sıcaklığına bağlı olarak 1 ila 7 dakika daha uzun olduğu görülmüştür. Hem yeşil hem de kırmızı biber dilimleri için tüm kurutma işlemi, genel olarak azalan oran şeklinde gerçekleşmiştir. Biber dilimlerinin kurutulması sırasında nem oranındaki değişikliklere uyum yönünden test edilen 11 matematiksel model arasından Midilli ve ark. (2002) modelinin en uygun model olduğu tespit edilmiştir. Kurutma katsayısı (k), kuruma sıcaklığının artmasıyla artış göstermiştir. Kızılötesi kurutma sıcaklığındaki artışla birlikte etkili nem yayılma değerlerinde önemli artışlar gözlenmiştir. Çalışılan kurutma sıcaklıklarına bağlı olarak, Deff değerleri; yeşil biber için 0.5363x10-10 ila 1.1369x10-10 m2s-1 ve kırmızı biber için 0.6079x10-10 ila 1.2561x10-10 m2s-1 arasında değişmiştir. 50°C'de ve 70°C'de kurutulan kırmızı biber dilimlerinin Deff değerleri, yeşil biber için olanlardan anlamlı miktarda yüksektir (P <0.001). Aktivasyon enerjisinin (Ea) yeşil biber için 34.69 kJ/mol ve kırmızı biber için 33.46 kJ/mol olduğu tahmin edilmiştir. Ea değerlerinin birbirine yakınlığı, olgunlaşmamış (yeşil) biberin, olgunlaşmış (kırmızı) biber kadar kızılötesi kurutma sıcaklığına hassas olduğu anlamına gelmektedir. Ayrıca, biberin yeşilden kırmızıya olgunlaşması, ısı transfer özelliklerini kontrol eden yapısal özelliklerinin çoğunu değiştirmemiştir. Kuruma zamanına göre nem içeriği ve kuruma oranı özellikleri de bu bulguları desteklemektedir.

Jahe merah kaya akan kandungan antioksidan dan bahan aktif, sehingga proses pengeringannya sebaiknya dilakukan dengan menggunakan suhu rendah. Pengeringan jahe merah pada suhu rendah dapat dilakukan dengan menggunakan cabinet dryer yang sumber pemanasnya berasal dari panas terbuang kondensor AC. Tujuan dari penelitian ini adalah untuk menguji kinerja cabinet dryer dengan sumber pemanas berasal dari panas terbuang kondensor AC, pada pengeringan jahe merah, dan dengan beberapa tingkat beban pengeringan yang berbeda. Pengujian kinerja dilakukan dengan bahan jahe merah sebanyak 600, 900, dan 1200 gram yang kemudian dibagi ke dalam 6 buah rak pengering. Pengamatan dan analisis data meliputi suhu pengeringan, kelembaban udara, kadar air, laju pengeringan, panas yang digunakan untuk meningkatkan suhu bahan, panas yang digunakan untuk menguapkan air bahan, kebutuhan energi untuk proses pengeringan, serta efisiensi energi. Hasil penelitian menunjukkan bahwa cabinet dryer dengan sumber pemanas berasal dari panas terbuang kondensor AC mampu mengeringkan jahe merah hingga mencapai kadar air 9.24-10.71% sesuai dengan standar SNI, dengan waktu pengeringan selama 6.5-8.7 jam. Energi yang terpakai untuk mengeringkan jahe merah berkisar antara 1281.67-2583.86 kJ. Efisiensi pengeringan yang dicapai dari tiap perlakuan berkisar antara 14.04-21.15%.

In order to evaluate evolution of physical and mechanical properties due to drying and heat modification, a load of radiata pine wood was selected and properties were measured after each drying process. The results revealed interesting correlations between intrinsic factors and properties; the values of density were highly dispersed after drying or thermal treatment and uncorrelated with others parameters, but the minimum density values were kept constant after heat-treatment. Moreover, weight loss (WL) and moisture content (MC) were decreasing proportionally to the treatment intensity, due to wood-water interactions, cell wall changes and thermal degradation of wood fractions. WL and MC were reasonably correlated with the dimensional stability, improving the dimensional stability after drying treatments but keeping the same order of anisotropy. Regarding the wood stiffness (MOE), it was unaffected by the drying temperature, and the correlations between MOE and MC or WL appear to be acceptable, and the values of MC or WL did not adversely affect the MOE. However, the modulus of rupture was dropped during the drying process, obtaining three differentiated groups with a decrease of around 59% after thermal modification

The Effect of Wood Drying and Heat Modification on Some Physical and Mechanical Properties of Radiata Pine.

The objective of this study is to evaluate the changes in physicochemical properties of pasteurized coconut milk at refrigeration condition. Four groups of samples, viz. sample-1: coconut milk from endosperm without testa, sample-2: coconut milk from endosperm with testa, sample-3: pasteurized coconut milk from endosperm without testa and sample-4: pasteurized coconut milk from endosperm with testa, were prepared for this study. Pasteurization was done by heating at a temperature of 72 ± 1°C for 15 minutes. The coconut milk samples were stored for 3 weeks in refrigeration condition (4°C). The biochemical analysis of coconut milk samples in terms of proximate composition, total solids, acidity and pH were determined and the total viable count method was applied for the evaluation of microbiological quality. The acceptability of coconut milk samples was assessed by visual observation and sensory evaluation. Results indicated that significant retention in nutrient content was observed in all samples during storage. Statistical analysis of sensory parameters (viz. color, flavor and taste) indicated an acceptable quality of coconut milk samples during storage. The total viable count of coconut milk samples was in an acceptable range of up to 3 weeks but fungal growth occurred after 2 weeks. Conclusively, coconut milk samples can be stored up to 2 weeks without affecting its overall acceptability.

Keskin M, Y Soysal, YE Sekerli, A Arslan, N Celiktas. 2019. Assessment of applied microwave power of intermittent microwave-dried carrot powders from Colour and NIRS. Agronomy Research. Vol.17, https://doi.org/10.15159/AR.19.071

ABSTRACT: Applied microwave (MW) power level is an essential factor on the quality of the dried agricultural products. Even if higher MW powers result in shorter drying times, they lead to quality degradations. It is almost impossible to know the applied MW power of a dried and powdered product by human vision. Thus, the aim of this study was to predict the applied MW power of carrot powders by using two different instruments, a chromameter and FT-NIRS. The experiments were carried out at nine different power levels (100–500 W) with three replications (N = 27). The colour and NIR reflectance was measured using a chromameter and NIRS system. The data was analysed using PLS regression. The drying time of intermittent MW drying at the highest applied power of 500 W was 1.12–5.47 times shorter than those of other lower applied powers. Applied MW power was a crucial factor on all colour parameters of the powdered carrots. Brightness (L*) decreased significantly with the increase of applied MW power resulting in darker product colours. Data analysis results showed that the NIRS system (R2 = 0.99; SEP = 16.1 W) can predict the microwave power of powdered carrots with significantly better performance than a chromameter (R2 = 0.95; SEP = 29.9 W). But, the chromamater is far more inexpensive when compared with the NIRS system and hence, it can also be used to predict the applied MW power from the colour data relatively well. Also, a mathematical model was developed to predict applied MW power from the colour parameters.

ÖZET: Mikrodalga (MW) güç seviyesi, mikrodalga ile kurutulan tarım ürünlerinin kalitesinde önemli bir faktördür. Yüksek MW gücü daha kısa kuruma süreleri sağlar ancak üründe kalite bozulmalarına neden olur. Mikrodalga ile kurutulmuş ve toz haline getirilmiş bir ürüne uygulanan MW gücünü insan gözü ile bilmek neredeyse imkansızdır. Bu nedenle, bu çalışmanın amacı, iki farklı cihazın (renk ölçer ve FT-NIRS) MW ile kurutulmuş havuç tozlarına uygulanan MW gücünü tahmin etmekde kullanım imkanını araştırmaktı. Kurutma deneyleri dokuz farklı güç seviyesinde (100–500 W) üç tekerrürlü olarak yapıldı (N = 27). Renk ve NIR yansıma değerleri, bir renk ölçer ve NIRS sistemi ile ölçüldü. Veriler PLS regresyonu kullanılarak analiz edildi. 500 W'lık en yüksek kesikli MW kurutma işlemindeki  kurutma süresinin, diğer düşük güçlere göre 1.12-5.47 kat daha kısa olduğu görülmüştür. Uygulanan MW gücünün, toz havuçların tüm renk parametrelerinde önemli bir faktör olduğu görüldü. Renk parlaklık (L*) değerinin, uygulanan MW gücünün artmasıyla önemli ölçüde azaldığı ve daha koyu renkli ürün ile sonuçlandığı görüldü. Bulgular toz havuca uygulanan MW gücünün NIRS sistemi ile (R2=0.99; SEP=16.1 W) renk ölçere kıyasla (R2 = 0.95; SEP = 29.9 W) önemli ölçüde daha iyi bir performansla tahmin edebileceğini gösterdi. Ancak, renk ölçer, NIRS sistemine kıyasla daha ucuzdur ve bu nedenle uygulanan MW gücünü, renk verilerinden nispeten iyi bir şekilde tahmin etmek için kullanılabilir. Ayrıca çalışmada, uygulanan MW gücünü renk parametrelerinden tahmin etmek için matematiksel bir model geliştirilmiştir.

The moisture dependent physical properties of
different lathyrus varieties namely NLK-40, Pratik and Ratan
were studied at moisture content of 7.33 to 30.29, 6.75 to
29.95 and 7.90 to 30.90% (d.b.), respectively. The grain size,
thousand grain weight, angle of repose, grain volume and
surface area were found increased linearly. The grain size was
found increased from 4.43 to 4.70, 4.96 to 5.32 and 5.08 to
5.49 mm. Thousand grain weight was found increased from
64.6 to 103.5, 69.1 to 105.3 and 85.3 to 125.6 g. The angle
repose was increased from 28.3 to 35.4, 29.5 to 35.8 and 26.9
to 33.5°. The grain volume was increased from 9.13 to
10.38,11.73 to 13.24 and 12.22 to 14.15 mm3 whereas,
surface area increased from 54.78 to 62.29, 70.38 to 79.45
and 73.31 to 84.88 mm2,respectively with the corresponding
increase in moisture content, for NLK-40, Pratik and Ratan.
The sphericity and porosity increased initially and then found
decreased with increase in further moisture content. The bulk
density values decreased linearly from 827.5 to 697.2, 851.3
to 726.3 and 856.0 to 727.4 kg/m3. The true density values
were found decreased from 1288.3 to 1074.3, 1324.0 to
1118.4 and 1277.7 to 1102.5 kg/m3, respectively for these
varieties with the corresponding increase in moisture content.