Alpha-L-arabinofuranosidase involved in xyloglucan degradation by mediating the cleavage of terminal non-reducing alpha-L-arabinofuranoside residues in xyloglucan branches, converting the 'S' units to 'X' units. Hydrolysis of terminal non-reducing alpha-L-arabinofuranoside residues in alpha-L-arabinosides. kcat is 0.0005 sec(-1) for L- Araf-alpha-PNP. Optimum pH is 6.0-7.0. Glucan metabolism; xyloglucan degradation. Periplasmic localization is predicted by analogy with the archetypal sus locus. Gut bacteria supply the human body with energy from dietary polysaccharides through glycosidases that are absent in the human genome. Xyloglucans are a ubiquitous family of highly branched plant cell wall polysaccharides present in the vegetables we consume. Enzymes involved in xyloglucan degradation mediate the conversion of otherwise indigestible plant polysaccharides to short-chain fatty acids (PubMed:24463512). Belongs to the glycosyl hydrolase 43 family. Truncated N-terminus.