Aysel ARSLAN, Yurtsever SOYSAL, Muharrem KESKİN

Comparing hot air drying kinetics and color quality of organic and conventional sweet red peppers

Aims: This study was conducted to compare the hot air drying kinetics and color quality of organically and conventionally produced sweet red peppers. Methods and Results: The pepper samples were dried at 60, 70 and 80°C using a hot air dryer. Drying kinetics, effective moisture diffusivity (Deff), activation energy (Ea) and color quality were studied. The drying process for both organic (OSRP) and conventional sweet red peppers (CSRP) occurred mainly in falling rate period. Increasing the drying temperature reduced the drying time considerably. Except 60°C, significant difference was found between the drying times of OSRP and CSRP samples. The Midilli model gave the best fit for all data points for pepper types. A positive relationship was found between the drying temperature and Deff values (OSRP: 39.6210-10 – 58.5810-10 m2 s -1 ; CSRP: 38.9210-10 – 57.5910-10 m2 s -1 ). Differences between the Deff values of OSRP and CSRP samples were not significant. Conclusions: Characteristic drying curve profiles, Deff and Ea values followed the similar trajectory showing that the growing practice of the peppers did not significantly change the structural features related to heat transfer. The hot-air drying at 70°C and 80°C gave brighter and redder pepper powders; hence, these treatments are suggested as the suitable drying applications to produce high quality OSRP and CSRP powders in terms of color quality. By using 80°C instead of 60°C, about 25% and 32% savings in drying times could be obtainable for CSRP and OSRP samples, respectively. Significance and Impact of the Study: Organic production has an increasing trend in the world; however, research on the evaluation of drying kinetics and color quality of organic products is very limited. Thus, this study aimed at studying appraisal of the drying kinetics and related parameters of CSRP and OSRP samples.

Organik ve konvansiyonel tatlı kırmızı biberlerin sıcak hava kurutma kinetiği ve renk kalitesinin karşılaştırılması

Amaç: Bu çalışma organik ve konvansiyonel olarak üretilen tatlı kırmızı biberlerin sıcak hava kurutma kinetiklerini ve renk kalitesini karşılaştırmak için yapılmıştır. Yöntem ve Bulgular: Biber örnekleri, sıcak hava kurutucuda 60, 70 ve 80°C’de kurutuldu. Kurutma kinetiği, efektif nem difüzyonu (Deff), aktivasyon enerjisi (Ea) ve renk kalitesi incelenmiştir. Hem organik (OTKB) hem de konvansiyonel tatlı kırmızı biberler (KTKB) için kurutma işlemi temel olarak azalan hızlı kurutma periyodunda gerçekleşmiştir. Kurutma sıcaklığının arttırılması, kuruma süresini önemli ölçüde azaltmıştır. 60°C haricinde, OTKB ve KTKB örneklerinin kuruma süreleri arasında önemli bir fark bulunmuştur. Midilli modelinin biber tipleri için tüm veri noktalarına en uygun verileri sağladığı tespit edilmiştir. Kurutma sıcaklığı ve Deff değerleri arasında (OTKB için 39.62x10-10 - 58.58x10- 10 m2 s -1 ve KTKB için 38.92x10-10 - 57.59x10-10 m2 s -1 ) pozitif bir ilişki bulunmuştur. Deff değerleri bakımından OTKB ve KTKB arasında dikkate değer bir fark bulunmamıştır. Genel Yorum: Karakteristik sıcak hava kurutma eğrisi profilleri, Deff ve Ea değerlerinin OTKB ve KTKB için benzer eğilimi izlediği ve kırmızı biberin yetiştirilme yönteminin ısı transferi ile ilgili yapısal özelliklerini önemli ölçüde değiştirmediği görülmüştür. 70°C ve 80°C'de sıcak hava ile kurutma, daha parlak ve daha kırmızı biber tozları sağladığından bu uygulamalar renk kalitesi açısından yüksek kaliteli OTKB ve KTKB tozları üretmek için uygun kurutma uygulamaları olarak önerilmektedir. 60°C yerine 80°C kullanılarak KTKB ve OTKB örnekleri için kurutma sürelerinde yaklaşık %25 ve %32 tasarruf sağlanabilmektedir. Çalışmanın Önemi ve Etkisi: Organik üretim dünyada giderek artan bir eğilime sahiptir; ancak organik ürünlerin kurutma kinetikleri ve renk kalitesi ile ilgili araştırmalar çok sınırlıdır. Bu nedenle, bu çalışmada OTKB ve KTKB örneklerinin kurutma kinetiği ve ilgili parametreleri değerlendirilmiştir.

PDF

___

Arslan, D, Ozcan, MM (2011). Dehydration of red bellpepper (Capsicum annuum L.): Change in drying behavior, colour and antioxidant content. Food and Bioproducts Processing, 89: 504-513.

Asami DK, Hong YJ, Barrett DM, Mitchell AE (2003). Comparison of the total phenolic and ascorbic acid content of freeze-dried and air dried marionberry, strawberry, and corn grown using conventional, organic, and sustainable agricultural practices. J. Agri Food Chem. 51: 1237–1241.

Bickel R, Rossier R (2015). Sustainability and quality of organic food. Research Institute of Organic Agriculture (FIBL) and the Organic Research Centre, Elm Farm (ORC).

Brandt K, Leifert C, Sanderson R, Seal CJ (2011). Agroecosystem management and nutritional quality of plant foods: the case of organic fruits and vegetables. Crit. Rev. Plant. Sci. 30(1-2): 177-197.

Cao Z, Zhou L, Bi J, Yi J, Chen Q, Wu X, Zheng J, Li S (2016). Effect of different drying technologies on drying characteristics and quality of red pepper (Capsicum frutescens L.): a comparative study. J. Sci. Food Agric. 96: 3596-3603.

Chen G, Mujumdar AS (2007) Drying of herbal medicines and tea, In: Handbook of Industrial Drying (Ed. Mujumdar AS), CRC Press: Boca Raton, FL, pp. 635– 646.

Crank J (1975). Mathematics of Diffusion. 2nd ed. Oxford University Press, London, pp. 414.

Darvishi H, Khoshtaghaza MH, Najafi G, Nargesi F (2013) Mathematical modeling of green pepper drying in microwave-convective dryer. J. Agric. Sci. Tech. 15: 457-465.

Deng LZ, Yang XH, Mujumdar AS, Zhao JH, Qian DW, Zhang JW, Gao ZJ, Xiao HW (2018) Red pepper (Capsicum annuum L.) drying: Effects of different drying methods on drying kinetics, physicochemical properties, antioxidant capacity, and microstructure. Dry Tech. 36(8): 893-907.

Diamente LM, Munro PA (1993). Mathematical modeling of the thin layer solar drying of sweet potato slices. Solar Energy, 51: 271-276.

DoymazI, Pala M (2002). Hot-air drying characteristics of red pepper. J. Food Eng. 55: 331–335.

Doymaz I, Ismail O (2011) Drying characteristics of sweet cherry. Food and Bioproducts Processing, 89: 31–38.

Ergunes G, Tarhan S (2006) Color retention of red peppers by chemical pretreatments during greenhouse and open sun drying. J. Food Eng. 76: 446–452.

Ertekin C, Yaldiz O (2004). Drying of eggplant and selection of a suitable thin layer drying model. J. Food Eng. 63: 349-359.

Fadhel A, Kooli S, Farhat A, Belghith A (2014) Experimental study of the drying of hot red pepper in the open air, under greenhouse and in a solar drier. Int. J. Renew. Energy Biof. Article ID: 515285, pp 14.

FAOSTAT (2020). Crop statistics database. Food and Agriculture Organization (FAO) of the United Nations, Rome, Italy. Retrieved April 13, 2020, from www.fao.org/faostat.

Gomiero T (2018) Food quality assessment in organic vs. conventional agricultural produce: Findings and issues. App. Soil. Ecol. 123: 714–728.

Hwang IM, Choi JY, Nho EY, Lee GH, Jamila N, Khan N, Jo CH, Kim KS (2017). Characterization of red peppers (Capsicum annuum) by high-performance liquid chromatography and near-infrared spectroscopy. Analy. Letters, 50(13): 2090-2104.

Jain D, Pathare PB (2004) Selection and evaluation of thin layer drying models for infrared radiative and convective drying of onion slices. Biosys. Eng. 89: 289- 296.

Kaleemullah S, Kailappan R (2005) Drying Kinetics of Red Chillies in a Rotary Dryer. Biosys. Eng. 92(1): 15–23.

Kaleemullah S, Kailappan R (2006) Modeling of ThinLayer Drying Kinetics of Red Chillies. J. Food Eng. 76(4): 531–537.

Kaymak-Ertekin F (2002) Drying and rehydrating kinetics of green and red peppers. J. Food Sci. 67(1): 168–175.

Keskin M, Setlek P, Demir S (2017) Use of color measurement systems in food science and agriculture. International Advanced Researches & Engineering Congress. November 16-18, Osmaniye, Turkey. pp 2350-2359.

Keskin M, Soysal Y, Arslan A, Sekerli YE, Celiktas N (2018) Predicting drying temperature of infrared-dried pepper powders using FT-NIRS and chromameter. International Conference on Energy Research, November 1-2, Alanya, Turkey. pp 305-319.

Keskin M, Soysal Y, Sekerli YE, Arslan A, Celiktas N (2019). Assessment of applied microwave power of intermittent microwave-dried carrot powders from colour and NIRS. Agronomy Research. 17(2):466-480.

Kim S, Park JB, Hwang IK (2002) Quality attributes of various varieties Korean red pepper powders (Capsicum annuum L.) and color stability during sunlight exposure. J. Food Sci. 67: 2957–2961.

Kumar N, Sarkar BC, Sharma HK (2011) Effect of air velocity on kinetics of thin layer carrot pomace drying. Food Sci. Tech. Int. 17: 439–447.

Lernoud J, Willer H (2019) Organic agriculture worldwide: Key results from the FiBL survey on organic agriculture worldwide Part 3: Organic agriculture in the regions. Research Institute of Organic Agriculture (FIBL), Frick, Switzerland. Madamba PS, Driscoll RH, Buckle KA (1996) The thinlayer drying characteristics of garlic slices. J. Food Eng. 29(1): 75–97.

Maskan A, Kaya S, Maskan M (2002). Hot air and sun drying of grape leather (pestil). J. Food Eng., 54: 81-88.

Midilli A, Kucuk H, Yapar Z (2002) A new model for singlelayer drying. Drying Tech. 20: 1503-1513. Moraes ICF, Sobral PJA, Branco IG, Gomide CA (2013) Dehydration of “dedo de moça” pepper: kinetics and phytochemical concentration. Cienc Tecnol. Aliment. Campinas, 33(Supl.1): 134-141.

Nasiroglu S, Kocabiyik H (2007) Thin-layer infrared radiation drying of red pepper slices. J. Food Process Eng. 33: 1-16.

Ramesh MN, Wolf W, Tevini D, Jung G (2001) Influence of processing parameters on the drying of spice paprika. J. Food Eng. 49: 63–72.

Rizvi SSH (1986) Thermodynamic properties of foods in dehydration, In Engineering Properties of Foods (Eds. Rao MA, Rizvi SSH), Marcel Dekker, New York, pp. 190-193.

Sablani SS, Andrews PK, Davies NM, Walters T, Saez H, Bastarrachea L (2011) Effects of air and freeze drying on phytochemical content of conventional and organic berries. Drying Tech. 29:205–216.

Sanjuan N, Lozano M, Garcia-Pascual P, Mulet A (2003) Dehydration kinetics of red pepper (Capsicum annuum L. var Jaranda). J. Sci. Food Agric. 83: 697– 701.

Saravacos GD (1986) Mass transfer properties of foods, In: Engineering properties of foods (Eds. Rao MA, Rizvi SSH), New York, Marcel Dekker Inc. pp 89-132.

Scala DK, Carpiste G (2008) Drying kinetics and quality changes during drying of red pepper. LWT, 41: 789– 795.

Soysal Y, Ayhan Z, Eştürk O, Arıkan MF (2009) Intermittent microwave–convective drying of red pepper: Drying kinetics, physical (colour and texture) and sensory quality. Biosys Eng. 103(4): 455-463.

Soysal Y, Keskin M, Arslan A, Sekerli YE (2018) Infrared drying characteristics of pepper at different maturity stages. International Conference on Energy Research, November 1-2, Alanya, Turkey. pp 293-304.

Soysal Y, Oztekin S, Eren Ö (2006) Microwave drying of parsley: Modelling, kinetics, and energy aspects. Biosys. Eng. 93: 403-413.

Soysal Y, Oztekin S, Isıkber AA, Duman AD, Dayısoylu KS (2005) Assessing the colour quality attributes of Turkish red chilli peppers (Capsicum annuum L.) and colour stability during storage. Proceedings of the 9th International Congress on Mechanization and Energy in Agriculture. September 27-29, Izmir, Turkey, pp. 99–104.

Taheri-Garavand A, Rafiee S, Keyhani A (2011) Study on effective moisture diffusivity, activation energy and mathematical modeling of thin layer drying kinetics of bell pepper. Australian J. Crop. Sci. 5(2): 128-131.

Thuwapanichayanan R, Prachayawarakorn S, Kunwisawa J, Soponronnarit S (2011) Determination of effective moisture diffusivity and assessment of quality attributes of banana slices during drying. LWT, 44(6): 1502-1510.

TMAF (2020) Organic agriculture production statistics of year 2018. Turkish Ministry of Agriculture and Forestry (TMAF). Retrieved May 17, 2020, from: www.tarimorman.gov.tr

Topuz A, Dincer C, Özdemir KS, Feng H, Kushad M (2011) Influence of different drying methods on carotenoids and capsaicinoids of paprika (Cv., Jalapeno). Food Chem. 129: 860–865.

Turhan M, Turhan KN, Sahbaz F (1997) Drying kinetics of red pepper. J. Food Process Preserv. 21: 209–223.

TurkStat (2018) Organic crop production statistics - 2018. Turkish Statistical Institute (TurkStat).

Vega A, Fito P, Andres A, Lemus R (2007) Mathematical modeling of hot-air drying kinetics of red bell pepper (var. Lamuyo). J. Food Eng. 79: 1460–1466.

Vega-Galvez A, Lemus-Mondaca R, Bilbao-Sainz C, Yagnam F, Rojas A (2008) Mass transfer kinetics during convective drying of red pepper var. Hungarian (Capsicum annuum L.): mathematical modeling and evaluation of kinetic parameters. J. Food Process Eng. 31: 120–137.

Verma LR, Bucklin RA, Endan JB, Wratten FT (1985) Effects of drying air parameters on rice drying models. Trans. ASAE, 28: 296-301.

Wang CY, Singh RP (1978) A single layer drying equation for rough rice. Trans ASAE paper no. 3001.

Wang Z, Sun J, Chen F, Liao X, Hu X (2007) Mathematical modeling on thin layer microwave drying of apple pomace with and without hot-air pre-drying. J. Food Eng. 80: 536-544.

Winter CK, Davis SF (2006) Organic foods. J. Food Sci. 71(9): R117-R124.

Yagcioglu A, Degirmencioglu A, Cagatay F (1999) Drying characteristics of laurel leaves under different drying conditions. Proceedings of 7th International Congress on Agricultural Mechanization and Energy in Agriculture, May 26-27, Adana, Turkey. pp 565-569.

Zogzas, N.P., Maroulis, Z.B., Marinos-Kouris, D., 1996. Moisture diffusivity data compilation in foodstuffs. Dry. Technol. 14(10): 2225–2253.