Comprehensive Review on Bulla: Uses and Nutritional, Cultural, and Processing Perspectives of an Enset-Derived Food in Ethiopia.

Abstract

Enset (Ensete ventricosum) is a perennial herbaceous monocot belonging to the Musaceae family. It is a crucial crop in Southern and Southwestern Ethiopia, providing food security for over 20 million people. The three main enset-derived food products are kocho, amicho, and bulla. Most studies have focused primarily on kocho, with much less attention given to the characteristics, production methods, and uses of bulla. Despite being traditionally regarded as the highest quality enset product and its considerable importance, the existing literature on bulla production contains significant inconsistencies. Additionally, much of the current literature does not clearly distinguish between bulla and fermented bulla; these two terms are often used interchangeably, which creates confusion. This review synthesized existing knowledge on bulla processing, nutritional profiles, socioeconomic roles, and medicinal applications. Following PRISMA guidelines, 337 records were identified through database searching. After removing 98 duplicate records, 77 records from nonreputable sources, and 79 papers that lacked clarity or rational justification, 83 articles remained and were assessed for full-text eligibility after rigorous screening. The result showed that bulla is primarily a product of mechanical juice extraction and sedimentation, not requiring fermentation for its primary form. It is an energy-dense product with high carbohydrate but low protein content. Kocho gives less energy yield (6.5 MJ/kg) than bulla (8.5 MJ/kg). Fermented bulla is produced using traditional fermentation methods that vary among households and localities, and standardized fermentation protocols have not yet been well established. However, fermented bulla might exist as a secondary variant with a scarcity of standardized protocols for its processing. Previous in vitro and tablet formulation studies have suggested that bulla starch may have potential as a pharmaceutical binder and as a gelling agent in biotechnological applications. This review urges further empirical research to standardize processes, maximize production, and expand bulla's applications for enhanced food security, medicinal uses, and economic benefit.