Infrared Drying Kinetics and Color Qualities of Organic and Conventional Sweet Red Peppers

Abstract

Bu çalışmada, üç farklı sıcaklıkta (60, 70 ve 80°C) kurutulan organik ve geleneksel olarak üretilen tatlı kırmızı biberlerin (Capsicum annum L.) kızılötesi kurutma kinetikleri, efektif nem difüzyonu, aktivasyon enerjisi ve renk kaliteleri karşılaştırılmıştır. Araştırma sonucunda, organik ve geleneksel tatlı kırmızı biberlerin kızılötesi kurutma sürecinin tamamının temel olarak azalan hızlı kurutma periyodunda meydana geldiği saptanmıştır. Kurutma sıcaklığındaki artışa bağlı olarak ürün kuruma süresi önemli ölçüde kısalmıştır. Organik ve geleneksel kırmızı biberlerin kurutma süreleri arasında anlamlı bir fark bulunmamıştır. Organik ve konvansiyonel biberlerin kuruma davranışına ilişkin tüm verilerin matematiksel olarak ifade edilmesinde Midilli modelinin in iyi sonuçları veren model olduğu belirlenmiştir. Midilli modelinin kurutma katsayısının kurutma sıcaklığındaki artışa bağlı olarak arttığı saptanmıştır. Organik biber örneklerinin efektif nem difüzyonu ve aktivasyon enerjisi değerlerinin geleneksel biber örneklerine ait değerlerden biraz daha yüksek olduğu belirlenmiştir. Bu sonucun Midilli modelinin kurutma katsayısı ve karakteristik kurutma hızı eğrileri ile uyum içinde olduğu saptanmıştır. Yüksek sıcaklıklarda kızılötesi kurutma ile tüketiciler tarafından daha çok tercih edilen, daha parlak renkte toz kırmızı biberler üretilebileceği belirlenmiştir. Organik biber örnekleri için 60°C'de kızılötesi kurutma uygulaması ile ürün renk kalitesi bakımından en iyi kırmızı toz biberlerin üretilebileceği saptanmıştır. Ayrıca, taze kırmızı biberlerin rengine en yakın renk kırmızılığı oranlarına ve taze kırmızı biberlerden daha yüksek parlaklık değerlerine sahip olan kırmızı biber tozları ürettikleri için, 60°C ve 70°C sıcaklıklarda kızılötesi ile kurutma uygulamaları da renk kalitesi bakımından kabul edilebilir kurutma uygulamaları olarak değerlendirilmiştir. Sonuç olarak, 60°C yerine 70°C'de kurutma uygulaması ile ürün kurutma süresinde yaklaşık % 22 tasarruf sağlamış olup, bu uygulamanın yüksek kaliteli organik veya geleneksel tatlı toz kırmızı biber üretmek için kullanılabileceği saptanmıştır.

Keywords

• kırmızı biber
• organik gıda
• renk kalitesi
• Kızılötesi kurutma
• Nem difüzyonu

Infrared Drying Kinetics and Color Qualities of Organic and Conventional Sweet Red Peppers

Abstract

This study compares the infrared drying kinetics, effective moisture diffusivity, activation energy and color qualities of organically and conventionally produced sweet red peppers (Capsicum annum L.) dried at three different temperatures (60, 70 and 80°C). Results showed that the entire drying process for both organic and conventional sweet red peppers took place mainly in falling rate period. Increasing the drying temperature decreased the drying time considerably. No significant difference was found between the drying times of organic and conventional red peppers. The Midilli model yielded the best fit for all data points for organic and conventional peppers. The drying coefficient of the Midilli model increased with the increase in the drying temperature. The effective moisture diffusivity and activation energy values of organic pepper samples were found slightly higher than those of the conventional samples. This result was found to be compatible with the drying coefficient of Midilli model and characteristic drying rate curves. Higher drying temperatures resulted in brighter red pepper powder color which is more preferable by consumers. Infrared drying at 60°C for organic pepper samples produced the best pepper powders in terms of color quality. Moreover, infrared drying at 60°C and 70°C was also judged as the acceptable drying applications in terms of color quality since they gave the nearest redness to yellowness ratios and higher brightness values as compared to the color of fresh peppers. Overall, infrared drying at 70°C instead of 60°C resulted in about 22% savings in drying time and can be used to produce high quality organic or conventional sweet red pepper powder with better color quality.

Keywords

• Red pepper
• organic food
• activation energy
• color quality
• Infrared drying
• Moisture diffusivity

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