ABSTRACT
Aloe barbadensis Miller (=A. vera (L.) Burm. f.) is the most common species of Aloe used in worldwide commerce and it is the only species of Aloe which productively yields gel from fillets. The three most critical factors in the production of A. barbadensis gel are (i) proper agronomy; (ii) the control of bacterial proliferation post leaf harvest; and, (iii) avoiding excessive activity of β1→ 4 glucosidases which will destroy the major glucomannan polysaccharide. Despite its appearance, Aloe is not a cactus and it grows best when supplied with an excess of 50 cm of water per year and a slight excess of nitrogen. Because of its somewhat unusual root system, aloes require well-drained soils and do not tolerate deep tillage. The control of bacterial growth during processing should focus on rapid processing of leaves, leaf and environmental sanitization, rapid cooling and processing of gel after filleting, and proper bacterial control. Microbiological analysis of aloe materials should be properly directed toward those organisms commensal with Aloe. The enzymes which break down major aloe polysaccharide can come from either the plant itself, be produced by contaminating organisms, or may be fungal enzymes added as processing aids. A lack of understanding of basic enzymology results in the very low level of polysaccharide observed in most of the less costly commercial aloe products. Because of the failure of so many companies in the industry to observe these guidelines and the presence of fraud in the ‘Aloe Vera’ industry, rigorous quality control must be performed by consumer product manufacturers. Lastly, recent scientific studies indicate that it may be very desirable to strongly control the level of anthraquinones in aloe extracts destined for dermatologic and cosmetic uses.
