Chia protein isolates (CPI) were obtained through isoelectric precipitation under two different conditions in order to compare their structural properties. Extraction was carried out at pH 10 or 12, whereas precipitation pH was fixed at 4.5. Samples were named as CPI10 or CPI12, according to their extraction pH (10 or 12, respectively). The recovery of chia proteins was higher when the extraction was carried out at pH 12 (17% for CPI12 and 13% for CPI10); however, CPI12 protein content (775g/kg) was slightly lower than CPI10 protein content (782g/kg). Both samples showed similar SDS-PAGE pattern. Protein dispersions of both isolates led to highly stabilized particles due to their negative ζ potential (around-54 mV). CPI10 has a higher proportion of small particles in suspension, revealed by a lower d3,2 value. Spectroscopic techniques showed that CPI10 presented higher content of β-helix than CPI12, resulting in higher thermal stability. This observation was supported by FT-IR spectroscopy since CPI10 presented less unordered structure than CPI12. The energy of endotherms obtained in CPI12 was considerably lower than in CPI10. Extraction at higher alkaline conditions led to a more denatured protein conformation with a higher content of random structure (18.1% for CPI10 and 22.9% for CPI12).

Please cite this article as: López, Dé.N., Ingrassia, R., Busti, P., Wagner, J., Boeris, V., Spelzini, Darí., Effects of extraction pH of chia protein isolates on functional properties, Abstract 24The aim of this work was to study the effect of the extraction pH on the functional 25 properties of chia protein isolates (CPI). Samples were named as CPI10 or CPI12, 26 according to their extraction pH, 10 or 12, respectively. Functional properties were 27 significantly modified by the extraction pH. Color properties revealed that CPI12 presented 28 a lower L* (47.8±0.9 for CPI10 and 30±1 for CPI12) due to enhanced protein-polyphenol 29 interactions. Besides, a higher b* value was obtained for CPI12 (7.0±0.3 for CPI12 and 30 5.6±0.7 for CPI10), as a result of a higher ash content. CPI12 showed a higher WAC 31 probably due to a higher exposure of polar amino acids (4.4±0.1 g/g and 6.0±0.2 g/g), 32 whereas CPI10 showed a higher ability to bind oil (7.1±0.2 g/g and 6.1±0.2 g/g for CPI10 33 and CPI12, respectively). CPI10 proved more appropriate as an emulsion stabilizer than 34 CPI12, which could be due to its higher surface hydrophobicity, protein solubility and 35 negative net charge. The d 4,3 (µm) was 29.5±0.4 and 20.4±0.3 in emulsions stabilized with 36 CPI12 and CPI10, respectively. Although both isolates underwent heat gelation, they 37 exhibited a weak gel behavior. Overall, CPI10 may be more suitable for the food industry 38 as a meat replacer or extender.39

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17Acid gelation of proteins is commonly used in the food industry and it can be induced 18 by the addition of glucono--lactone (GDL). The aim of this work was to use textural 19 analysis of images in order to assess possible changes in the microstructure of bovine 20 sodium caseinate (NaCAS) and soy protein isolate (SPI) acid gels. The gelation rate of 21 NaCAS related to the amount of GDL was evaluated. Also, the effect of the presence of

and textural characteristics of soy protein isolate and tara gum cold-set gels, LWT -Food Science and Technology (2019), doi:

Microstructural, rheological, and textural behaviour of tara gum-bovine sodium caseinate aqueous mixtures and their acid gels were evaluated. Acid gels with different microstructures and texture were obtained. These results can be related to a competition between the protein 2 acid gelation process and the segregative phase separation. Depending on the concentration ratio of both biopolymers, a continuous protein gel network or a water-in-water emulsion stabilized by acid gelation were observed. These findings may be used to address the development of new food grade gels with different textures and also for the obtention of protein microgels to encapsulate hydrophilic compounds.

In this work, a simple method to exploit protein and lipids from cheese‐whey by means of coacervation was studied. Initially, alginate and carboxymethylcellulose were tested, and the effect of pH and polymer concentration on protein solubility was determined to find the more adequate phase separation conditions. Protein and fat coacervation were carried out by the addition of carboxymethylcellulose to raw cheese‐whey, acidification to pH 3, and 6 hr incubation. This method showed 100% and 60% of fat and protein recovery yields, respectively, involving few operation steps and no need for complex equipment. The wet coacervate obtained was tested as a bread ingredient instead of milk and butter. The bread formulated with cheese ‐ whey protein coacervate showed a higher moisture content, springiness, and cohesiveness as well as a lower fat/lipid content and hardness when compared to the control bread what would make it appropriate for consumers. Novelty impact statement Proteins and fat were recovered from cheese whey by coacervation with carboxymethylcellulose. This is a simple process, suitable for small dairy industries and does not require expensive equipment or high energy supply. The protein‐fat concentrate was applied in bread formulation with appropriate functional properties.

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