Alpha-lactalbumin (␣-La), a globular protein found in all mammalian milk, has been used as an ingredient in infant formulas. The protein can be isolated from milk using chromatography/gel filtration, membrane separation, enzyme hydrolysis, and precipitation/aggregation technologies. ␣-La is appreciated as a source of peptides with antitumor and apoptosis, antiulcerative, immune modulating, antimicrobial, antiviral, antihypertensive, opioid, mineral binding, and antioxidative bioactivities, which may be utilized in the production of functional foods. Nanotubes formed by the protein could find applications in foods and pharmaceuticals, and understanding its amyloid fibrils is important in drawing strategies for controlling amyloidal diseases. Bioactive peptides in ␣-La are released during the fermentation or ripening of dairy products by starter and nonstarter microorganisms and during digestion by gastric enzymes. Bioactive peptides are also produced by deliberate hydrolysis of ␣-La using animal, microbial, or plant proteases. The occurrence, structure, and production technologies of ␣-La and its bioactive peptides are reviewed.

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Whey protein isolate (WPI) was hydrolysed to whey protein hydrolysates (WPH) of degree of hydrolysis equal to 15% using Protease N 'Amano' G (IUB 3.4.24.28) in a batch reactor at 55°C and pH 7.0 according to the pH-stat procedure. Ash was removed by adsorbing WPH onto macroporous adsorption resins (MAR). Following rinsing with deionised water, desorption was achieved by washing with 20%, 40% and 75% alcohol (v v )1 ) to obtain the three fractions HS20, HS40 and HS75. Ash reduced from 15.71% (WPH) to 4.38% (HS20), 2.02% (HS40) and 2.38% (HS75). Similarly, the protein content was enriched from a low of 64.89% (WPH) to 94.74% (HS20), 95.32% (HS40) and 92.00% (HS75). The fractions were analysed for surface hydrophobicity (SH o ), angiotensin-I converting enzyme (ACE) inhibition, emulsifying activity index, total amino acids composition and molecular weight distribution. Fraction HS75 was objectionably bitter, showed superior ACE inhibition (lowest IC 50 ), had the highest content of hydrophobic and essential amino acids and contained about 71% of <600 Da with no fractions exceeding 4142 Da. Desorption with alcohol weakened the hydrophobic interaction forces between the peptides and resins and hence eluted the peptides, with the bitter HS75 being extracted.