Food protein aggregates as vitamin-matrix carriers: Impact of processing conditions

• Published in: Food chemistry Vol. 134; no. 4; pp. 2141 - 2148
• Main Authors: Relkin, Perla, Shukat, Rizwan
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15-10-2012; Elsevier
• Subjects: Agricultural sciences; Biological and medical sciences; denaturation; dispersions; Food Handling; Food industries; Fundamental and applied biological sciences. Psychology; homogenization; Hot Temperature; Life Sciences; Milk Proteins - chemistry; molecular weight; Nanoparticles; Particle Size; Pressure; Protein aggregates; Protein Binding; Protein denaturation; protein sources; tryptophan; Vitamin matrix carrier; vitamins; Vitamins - chemistry; Vitamin–protein interactions; wavelengths; whey protein; Whey Proteins; Nanoparticles; Vitamin–protein interactions; Protein denaturation; Protein aggregates; Vitamin matrix carrier; Vitamin-protein interactions; Denaturation; Interaction; Vitamin; Aggregate; Protein; Food; SOY PROTEIN; BOVINE BETA-LACTOGLOBULIN; STABILITY; RESOLUTION; ALPHA-TOCOPHEROL; WHEY PROTEINS; NANOPARTICLES; TEMPERATURE; HIGH-PRESSURE HOMOGENIZATION; EMULSIONS
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2012.04.020

► Heat and high-pressure treatments for production of vitamin-loaded protein aggregates. ► Increasing high-pressure conditions led to lower particle size and polydispersity. ► Addition of vitamin increased particles size and charges and protein structural changes. ► Longer-term stability of vitamin in protein dispersions formed at higher pressure.
We studied the ability of protein aggregates for loading and protection of α-tocopherol, a model of heat- and light-sensitive bioactive compounds. Aqueous dispersions of whey proteins (4.5wt.%, pH 6.7) in the absence and presence of α-tocopherol (4wt.%) were prepared using an ultradisperser (10,000rpm for 10min and 65°C), and then submitted to further high-pressure homogenisation (HPH) at 300 or 1200bar for 12cycles. Relative to free-vitamin dispersions, increasing HPH conditions in the presence of vitamin led to higher protein denaturation, more tryptophan quenching and wavelength blue-shift (by 10nm), in parallel with increased zeta potential values (by −10mV), particle sizes (by 50%), and newly formed protein dimers, trimers and high molecular weight aggregates. As a result, the degree of vitamin degradation under increasing HPH and long-term storage was shown to decrease from 66% (ultradisper) to 50%, or to 30% (subject to further treatments at 300 or 1200bar, respectively).