Currently, food industries use supplements fromAloe veraas highly concentrated powders (starting products), which are added to the final product at a concentration of 1x, meaning 10 g/L for decolourized and spray-dried whole leaf powder (WLP) or 5 g/L for decolourized and spray-dried inner leaf powder (ILG) and also for nondecolourized and belt-dried inner leaf powder (ILF). Flavonoids, tannins, or saponins could not be detected for any starting product at this concentration and their total phenol concentration of 68–112 μM gallate-eq. was much lower than in fresh extract; however, their antioxidant capacity of 90–123 μM ascorbate-eq. for DPPH was similar to the fresh extract. Starting products, dissolved at 1x, had an aloin concentration of 0.04 to 0.07 ppm, a concentration much lower than the industry standard of 10 ppm for foodstuff. While decolourized starting products (i.e., treated with activated carbon) exhibited low cytotoxicity on HeLa cells (CC50= 15 g/L ILG or 50 g/L WLP), ILF at CC50= 1–5 g/L exhibited cytotoxic effects, that is, at concentrations even below the recommended for human consumption. Probable causes for the cytotoxicity of ILF are the exposure to high temperatures (70–85°C) combined with a high fibre content.

Food industries typically use Aloe vera as concentrated (100× to 200×) and dried powders in their final products. These powders are obtained by extrusion of Aloe inner leaf gel (ILG) or Aloe whole leaf (WLP); the juice is filtered through diatomaceous earth and activated carbon before spray drying at temperatures below 70 °C. In another process, Aloe inner leaf gel was dried at ~80 °C and mashed to a powder rich in high molecular weight fibres and soluble polysaccharides (ILF). In contrast to ILG and WLP, the ILF sample was cytotoxic for the human intestinal cell line Caco-2 (CC50 = 1 g/l), even at concentrations below the recommended dose for human consumption. At lower concentrations (250 mg/l) with LPS challenged macrophage-like THP-1 cells decreased by 40% the release of the anti-inflammatory cytokine IL-10, whereas the release of the proinflammatory cytokine IL-1β increased by 35% (compared to untreated but challenged macrophage-like THP-1 cells). Unexpectedly, under the same conditions, the less cytotoxic ILG and WLP, both samples with a lower fibre content, significantly increased (up to 2.4 times) the release of IL-10, while the concentration of IL-1β remained unaltered and of TNFα decreased by 35%. Even more interesting is that a treatment of the ILF sample with activated carbon reduced its cytotoxicity and increased the IL-10 release (3.1 times). Based on these results, we suggest applying an activated carbon treatment on Aloe-starting products, which have high fibre content and have received high temperature treatment, in order to reduce their cytotoxicity and improve their immunomodulatory properties.