Vol:.(1234567890) Journal of Food Measurement and Characterization (2018) 12:1686–1694 https://doi.org/10.1007/s11694-018-9784-6 1 3 ORIGINAL PAPER Efect of grinding methods on powder quality of king chilli Singam Suranjoy Singh 1  · Bhupendra M Ghodki 2  · T. K. Goswami 1 Received: 17 October 2017 / Accepted: 14 March 2018 / Published online: 16 March 2018 © Springer Science+Business Media, LLC, part of Springer Nature 2018 Abstract The article aims to investigate the infuence of cryogenic and ambient grinding on powder quality of king chilli (Capsicum chinense L.). The grinding experiments were performed using a laboratory scale ball mill. Quality of the powders was accessed by measuring the properties such as densities, Hausner ratio, compressibility index, particle size distribution, colour change, microstructural changes, and mineral compositions. Bulk density (483 kg m −3 ) and tapped density (556 kg m ‒3 ) of ambient ground powder was relatively higher than that of cryo-ground powder, (bulk density 414 kg m ‒3 and tapped density 480 kg m ‒3 ). However, Hausner ratio and compressibility index of ambient ground chilli powder were signifcantly lower than that of cryo-ground powder. The surface morphology, shape, and size of particles of cryo-ground powder were comparatively smoother, regular and smaller in size. Moreover, the major mineral (K) content and the colour (redness, yel- lowness, and lightness) were found to be relatively superior for cryo-ground powder. The overall results showed cryogenic grinding provides a better and fner quality ground powder than the conventional grinding methods. The results of this study will provide the spice industries, an opportunity to select the better grinding method based on the fow and sensory quality of the powder. The powder properties may further be utilized in the process modelling and design of packaging, grinding and handling equipment. Keywords Cryogenic grinding · Tapped density · Hausner ratio · Compressibility index · Morphology Introduction Spices are among the most demanding agricultural prod- ucts in the world due to distinct pungency, aroma, taste and appetizing senses. The spices can be used for diferent pur- poses such as favoring and preserving agent in foods, in pharmaceuticals and cosmetics. India is well known as “The Spice Bowl of the World” [1–3] and is the leading producer, exporter, and consumer of the fnest quality of spices in the world. A total of 109 spices are reported by ISO, out of which India shares around 69% [4]. Chillies are one of the major spices produced in India which belong to the genus Capsicum of family Solanaceae. Chillies are globally known for its distinct sensory attributes such as pungency, favour, and colour; hence, became an integral part of our diet. They can be used for various purposes such as to impart pun- gent favour in food, natural plant colour, pharmaceutical ingredients, riot control spray and self-defence, especially for women. The pungent favour of chillies is because of a chemical group of a related alkaloid called capsaicinoids which is present only in the genus Capsicum [5]. There are more than 400 diferent varieties of chillies found all over the world. King chilli (Capsicum chinense L.) is one the hottest chilli in the world and is cultivated mainly in the hilly terrain of Assam, India. It is also grown in other states of North-East India viz. Manipur, Nagaland and Mizo- ram and known by diferent local names, for example, Bhut Jolokia in Assam, Umorok in Manipur, Naga chilli in Naga- land, etc. This wonder spice has various varieties which are grown for condiments, vegetables, sauces and pickles pur- poses. Chilli plays an important role in our day today’s diet. Chilli is an inseparable spice item in everyone’s kitchen, * Singam Suranjoy Singh suranjoy1425@gmail.com * Bhupendra M Ghodki bhupendramghodki@gmail.com * T. K. Goswami tkg@agfe.iitkgp.ernet.in 1 Agricultural and Food Engineering Department, Indian Institute of Technology Kharagpur, Kharagpur 721302, India 2 Horticultural Crops Processing Division, ICARCentral Institute of Post-Harvest Engineering and Technology, Abohar 152116, India