Alpha 1 4 lsc christ freeze dryer

The water-soluble peptide extracts (WSPE) from yogurts and heat-treated reconstituted skim milk (pHadjusted to 4.5 ± 0.05) were prepared according to Sah et al. (2014) (link) with a few modifications. Briefly, samples were centrifuged at 22,680 × g using JLA-16.250 rotor in Avanti J-26S XPI High-Performance Centrifuge (Beckman Coulter Inc., Brea, CA) for 30 min at 4°C. The supernatant was filtered using a sintered glass crucible to remove coagulated proteins, debris, and cells. The filtrate was freeze-dried using an Alpha 1-4 LSC Christ freeze dryer (Martin Christ Gefriertrocknungsanlagen GmbH) at 0.1 mbar for 24 to 36 h (main drying) and 0.08 mbar for 12 h (final drying) and stored at -80°C until further analysis. The protein content (mg/mL) of the WSPE was estimated according to Bradford (1976) using BSA (0.1-1.4 mg/mL) as standards.
The WSPE were also profiled using a reversed-phase HPLC system as described by Sah et al. (2014) (link). Briefly, the samples were loaded using a 20-μL injection loop to a Varian HPLC system (Varian Inc., Palo Alto, CA) equipped with a C-18 monomeric column (5 μm, 300 Å, 250 × 4.6 mm; Grace Vydac, Hesperia, CA) and detected eluted peptides at 215 nm.

Pineapple peel powder was prepared from the peel of pineapples [Ananas comosus (L.) Merrill], as described by do Espírito Santo et al. ( 2012) with some modifications. Briefly, crushed peel (~2 × 2 cm sizes) was washed by dipping in hot water (90°C) for 30 min to inactivate potential pathogens and proteolytic enzymes (Jutamongkon and Charoenrein, 2010) . The peel was then freeze-dried using an Alpha 1-4 LSC Christ freeze dryer (Martin Christ Gefriertrocknungsanlagen GmbH, Osterode, Germany). The dried peel was milled to fine powder, standardized particle size less than 180 μm using wire mesh sieves (Endecotts Ltd., London, UK; Mesh Series BS410/1986) and sterilized with UV irradiation for 30 min (Coman et al., 2013) (link).

Water-soluble peptide extracts (WSPE) were prepared by high-speed centrifugation of yogurt samples as described by Sah et al. (2014) (link). Briefly, samples were centrifuged at 22,680 × g using a JLA-16.250 rotor in an Avanti J-26S XPI High-Performance Centrifuge (Beckman Coulter Inc., Brea, CA) at 4°C for 30 min. The supernatant was collected and freeze-dried using an Alpha 1-4 LSC Christ freeze dryer (Martin Christ Gefriertrocknungsanlagen GmbH, Osterode, Germany) and stored at -80°C until further analysis. The protein content (mg/mL) of the WSPE was estimated according to Bradford (1976) using BSA (0.1-1.4 mg/mL) as standard.