Thin-Layer Infrared Drying of Mint Leaves

Abstract

The effects of drying temperature on the drying time, color and thin‐layer drying model were investigated. The moisture ratios changes during the drying time were compared by 38 different mathematical models and evaluated by different statistical criteria such as coefficient of determination (R2), reduced chi‐square (χ2), root mean square error and mean relative percentage error (P). According to the results, drying time was between 18 and 38 min at drying temperatures of 60–80C. The lightness and yellowness of the dried mint leaves were significantly increased when compared with fresh samples. The high drying temperature yielded in darker, less green and more yellow mint leaves. When the 38 models compared according to the statistical values, the rational function model (model‐32) for drying temperatures of 60 and 70C and Modified Henderson Pabis‐II model (model‐5) were superior to the others. Practical Application Mint essential oil is extracted either from freshly harvested mint leaves or from semi dried or dried leaves through distillation process for industrial use. Therefore, mint drying by using infrared provides many advantages.

Infrared Drying and Effective Moisture Diffusivity of Apricot Halves: Influence of Pretreatment and Infrared Power

“…; Kocabiyik et al . ), mint (Ertekin and Heybeli, ) and others. There has been some works on drying of apricot, including Togrul and Pehlivan () under open‐air sun, Doymaz (), Faal et al .…”

“…The infrared drying is particularly suitable for thin layers of material with large surface exposed to radiation. Some studies have reported on the effects of infrared application and/or by a combined infrared-assisted convection process such as apple (Nowak and Lewicki, 2004), pineapple (Ponkham et al 2012), tomato (Corre a et al 2012Kocabiyik et al 2015), mint (Ertekin and Heybeli, 2014) and others. There has been some works on drying of apricot, including Togrul and Pehlivan (2004) under open-air sun, Doymaz (2004), Faal et al (2015 and Dai et al (2015) by hot-air dryers, Fahloul et al (2009) by freeze dryer and Garcia-Martinez et al (2013) by combined hot-air and microwave dryer.…”

Experimental Study and Mathematical Modeling of Thin-Layer Infrared Drying of Watermelon Seeds

“…Several agricultural products and by-products have been successfully dried by the infrared application and/or by a combined infrared-assisted convection process such as apple slice (Nowak and Lewicki 2004), onion (Sharma et al 2005), peach (Wang and Sheng 2006), sweet potato (Lin et al 2005), apple pomace (Sun et al 2007), red pepper (Nasiroglu and Kocabiyik 2009), tomato by-products (Ruiz Celma et al 2009), sweet potato (Doymaz 2012) and mint (Ertekin and Heybeli 2013). Several agricultural products and by-products have been successfully dried by the infrared application and/or by a combined infrared-assisted convection process such as apple slice (Nowak and Lewicki 2004), onion (Sharma et al 2005), peach (Wang and Sheng 2006), sweet potato (Lin et al 2005), apple pomace (Sun et al 2007), red pepper (Nasiroglu and Kocabiyik 2009), tomato by-products (Ruiz Celma et al 2009), sweet potato (Doymaz 2012) and mint (Ertekin and Heybeli 2013).…”

“…Application of infrared radiation to food processing has gained attention due to its inherent advantages over hot air heating. Several agricultural products and by-products have been successfully dried by the infrared application and/or by a combined infrared-assisted convection process such as apple slice (Nowak and Lewicki 2004), onion (Sharma et al 2005), peach (Wang and Sheng 2006), sweet potato (Lin et al 2005), apple pomace (Sun et al 2007), red pepper (Nasiroglu and Kocabiyik 2009), tomato by-products (Ruiz Celma et al 2009), sweet potato (Doymaz 2012) and mint (Ertekin and Heybeli 2013). However, the infrared drying process of watermelon seed has not been investigated in literature.…”

Process efficiency of electromagnetic radiation (EMR)‐assisted hybrid drying in spearmint ( Mentha spicata L. )

“…Carvone is a major volatile compound present in spearmint essential oil, giving its characteristic odor (Telci, Sahbaz, Yilmaz, & Tugay, ). Spearmint leaves are highly perishable due to its high moisture content (78%–83% wb) (Ertekin & Heybeli, ) and to improve its shelf life, postharvest processing is required. Conventionally, sun drying or hot air (HA) drying is used as a postharvest processing technique to extend the shelf life (Therdthai & Zhou, ).…”