<div>Background: The development of post-harvest equipment or machinery is vital for agricultural productivity. Bixin, a natural colourant derived from annatto seeds, is still separated manually, which may result in pigment loss. The engineering properties of annatto fruits and seeds must be analyzed in this note for the development of a mechanical seed separator. 
 
Methods: The fruits were collected from Forest College and Research Institute, TNAU, Mettupalayam, Tamil Nadu. Engineering properties such as physical, gravimetric and frictional properties, colour and bixin content were determined for two dried annatto fruit and seed varieties (A1 and A2). The Z-test and t-test (p&lt;0.05) were used to statistically analyze the data. 
 
Result: The morphological characteristics of annatto fruits A1 and A2 differed noticeably and significantly. The surface area and volume of the A1 fruit were higher. The fruit and seed were merely spherical and conical. The lowest static friction was observed for stainless steel in both fruit and seeds. The mean bixin content of the A1 and A2 seeds was 1.5&plusmn;0.4% and 1.84&plusmn;0.57%, respectively. These engineering properties will be used to design a mechanical separator without much loss of pigment.</div>

Morphological Assessment of Annatto (Bixa orellana L.) Fruit and Seed for the Development of Mechanical Seed Separator

Background: Concerns over the environmental and health hazards of using synthetic dyes, resulted in growing interest of using natural resources in textile printing sector. The artisans use different techniques and methods based on the availability of natural sources. &nbsp; 
 
Methods: The present study explores the effectiveness of guar gum and tamarind seed powder (TSP) as natural thickening agents in developing eco-friendly print pastes for silk fabric using natural dyes. Six print paste combinations were formulated using annatto, arjuna and madder dye along with auxiliaries such as chitosan, alum, coconut oil and myrobalan. The natural dye was extracted by aqueous extraction method followed by ultra-sonication of the dye extract. 
 
Result: The results revealed that guar gum-based combinations exhibited superior design quality compared to TSP. Among all samples, the combination containing arjuna dye with guar gum (PPC 02) achieved the highest mean score (4.53) followed by annatto with guar gum (PPC 01). Whereas, TSP combinations with annatto and arjuna showed poor performance while the madder dye combination (PPC 06) demonstrated better results comparable to guar gum. 
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Morphological Assessment of Annatto (Bixa orellana L.) Fruit and Seed for the Development of Mechanical Seed Separator

Development of Direct Printing Paste for Silk Printing and its Efficacy for Colour Fastness