A novel enzymatic approach based on the use of multi-enzymatic systems for the recovery of enriched protein extracts from potato pulp

Potato protein: An emerging source of high quality and allergy free protein, and its possible future based products

Recently protein has gained eminence due to awareness and demand for healthy food. Potato proteins are extracted from potato fruit juice and industrial potato waste; its nutritional and functional values have been found more significant than other vegetables and cereal proteins. Potato proteins can be easily extracted by various separation techniques, including an ion exchange (IEX) and expanded bed adsorption (EBA), and their functional properties can be modified for desire purposes. It contains many essential amino acids necessary for the human body, with an amino acid score (AAS) of 65%. Recent research on potato proteins resulted in several descriptions of new technologies to produce food-grade potato protein. It has recently drawn more attention as a protein source for human consumption, especially as an allergy free protein source and selective activity against cancer cells. Growing shreds of evidence have highlighted that potato protein can be used in many upcoming nutraceuticals and allergy-free food products. Therefore it is gaining more attention from nutritionists and food scientists. This review has summarized the recent knowledge on the nutritional and functional aspects of potato proteins, especially its non-allergic properties, enhancement in functional properties, and possible future-based products.

Potato Industry By-Products as a Source of Protein with Beneficial Nutritional, Functional, Health-Promoting and Antimicrobial Properties

Most potato proteins are fractions of albumin and globulin, soluble in water and in water and salt solutions, respectively; these are patatin glycoproteins, with a pIs in the range of 4.8–5.2. This group of proteins is typical of potato and they are referred to as patatin or tuberin. Around 30–50% of soluble potato proteins comprise numerous fractions of protease inhibitors with a molecular weight in the range of 7–21 kDa; they are often heat-resistant, showing a wide spectrum of health-promoting effects. The nutritional value of proteins is related to the content of amino acids, their mutual proportions and digestibility. Natural proteins of the patatin fraction are characterized by favorable functional properties, including foam formation and stabilization, fat emulsification or gelling. Native potato proteins may also exhibit beneficial non-food properties, such as antimicrobial or antitumor, as well as antioxidant and antiradical. Depending on the method of isolation and the applied factors, such as pH, ionic strength and temperature, the directions of using potato protein preparations will be different.

Non-animal proteins as cutting-edge ingredients to reformulate animal-free foodstuffs: Present status and future perspectives

Consumer interest in protein rich diets is increasing, with more attention being paid to the protein source. Despite the occurrence of animal proteins in the human diet, non-animal proteins are gaining popularity around the world due to their health benefits, environmental sustainability, and ethical merit. These sources of protein qualify for vegan, vegetarian, and flexitarian diets. Non-animal proteins are versatile, derived mainly from cereals, vegetables, pulses, algae (seaweed and microalgae), fungi, and bacteria. This review's intent is to analyze the current and future direction of research and innovation in non-animal proteins, and to elucidate the extent (limitations and opportunities) of their applications in food and beverage industries. Prior knowledge provided relevant information on protein features (processing, structure, and techno-functionality) with particular focus on those derived from soy and wheat. In the current food landscape, beyond conventionally used plant sources, other plant proteins are gaining traction as alternative ingredients to formulate animal-free foodstuffs (e.g., meat alternatives, beverages, baked products, snack foods, and others). Microbial proteins derived from fungi and algae are also food ingredients of interest due to their high protein quantity and quality, however there is no commercial food application for bacterial protein yet. In the future, key points to consider are the importance of strain/variety selection, advances in extraction technologies, toxicity assessment, and how this source can be used to create food products for personalized nutrition.

Study on rapid drying and spoilage prevention of potato pulp using solid-state fermentation with Aspergillus aculeatus

Effects of solid-state fermentation on rapid drying and spoilage prevention of potato pulp were evaluated. Pectin hydrolyzing and antibacterial ability of pectinase-secreting Aspergillus aculeatus and Bacillus subtilis were compared. A. aculeatus grew better in potato pulp, with highest pectinase yield of 342.71 ± 5.09 U/mL and rapid pH reduction to 3.76 ± 0.01. Next generation sequencing showed that the abundance of genera Candida and Enterobacter, which probably caused undesirable fermentation and spoilage, were significantly reduced after inoculation with A. aculeatus. In addition, fermentation with A. aculeatus significantly reduced water holding capacity from 16.63 ± 0.36 g/g to 7.78 ± 0.12 g/g, which resulted in lower viscosity and water binding capacity, and concomitantly significantly decreased moisture content from 76.05 ± 0.24% to 12.95 ± 0.19% after filtration and airflow drying. These results suggested that solid-state fermentation might be a promising technology for efficient processing and utilization of potato pulp.

The Nutritional Value and Biological Activity of Concentrated Protein Fraction of Potato Juice

Potato protein is recognized as one of the most valuable nonanimal proteins due to the high content of essential amino acids. So far, it has not been used in human nutrition on a large scale due to technological limitations regarding its acquisition. In this study, the protein fraction of potato juice was concentrated with the use of membrane separation. The obtained potato juice protein concentrate (PJPC) was characterized in terms of nutritional value and biological activity, and the amino acid composition, mineral content, and antioxidant properties were determined. Moreover, in vitro cytotoxic activity against cancer cells of the gastrointestinal tract was investigated. The results of the present study indicate that PJPC is an excellent source of lysine and threonine, while leucine is its limiting amino acid, with an amino acid score (AAS) of 65%. Moreover, PJPC contains substantial amounts of Fe, Mn, K, and Cu. As demonstrated experimentally, PJPC is also characterized by higher antioxidant potential than potato itself. Biological activity, however, is not limited to antioxidant activity alone. Cytotoxicity studies using a gastric cancer cell line (Hs 746T), a colon cancer cell line (HT-29), and human colon normal cells (CCD 841 CoN) proved that PJPC is characterized by selective activity against cancer cells. It can thus be concluded that the developed method of producing protein concentrate from potato juice affords a product with moderate nutritional value and interesting biological activity.

Association of Patatin-Based Proteomic Distances with Potato ( Solanum tuberosum L.) Quality Traits

Patatin is the major tuber storage protein constituted by multiple isoforms highly variable across potato ( S. tuberosum) varieties. Here, we report a first association study of the variability of patatin isoforms between cultivars with their differences in tuber quality traits. Patatin-based proteomic distances were assessed between 15 table and/or processing potato cultivars from profiles of patatin obtained by two-dimensional electrophoresis. The content of ash, dry matter, reducing sugars, starch, total protein, and amino acid composition was also evaluated in tubers of each cultivar. Results showed that proteomic distances were significantly ( P < 0.05) associated with differences in the content of ash, dry matter, and essential amino acids. Proteomic distances were also able to identify outlier cultivars regarding the content of dry matter, content of protein, and protein quality. In conclusion, patatin-based proteomic distances can shorten the screening and selection processes of potato cultivars with advantageous characteristics in molecular breeding.

Improving the enzymolysis efficiency of potato protein by simultaneous dual-frequency energy-gathered ultrasound pretreatment: Thermodynamics and kinetics

The thermodynamics and kinetics of traditional and simultaneous dual frequency energy-gathered ultrasound (SDFU) assisted enzymolysis of potato protein were investigated to get the knowledge of the mechanisms on the SDFU's promoting efficiency during enzymolysis. The concentration of potato protein hydrolysate and parameters of thermodynamic and kinetic during traditional and SDFU assisted enzymolysis were determined. The results showed that potato protein hydrolysate concentration of SDFU assisted enzymolysis was higher than traditional enzymolysis at the hydrolysis time of 60min (p<0.05) whereas not significantly different at 120min (p>0.05). In some cases, SDFU assisted enzymolysis took less hydrolysis time than traditional enzymolysis when the similar conversion rates of potato protein were obtained. The thermodynamic papameters including the energy of activation (E_a), enthalpy of activation (△H), entropy of activation (△S) were reduced by ultrasound pretreatment while Gibbs free energy of activation (△G) increased little (1.6%). Also, kinetic papameters including Michaelis constant (K_M) and catalytic rate constant (k_cat) decreased by ultrasound pretreatment. On the contrary, reaction rate constants (k) of SDFU assisted enzymolysis were higher than that of traditional enzymolysis (p<0.05). It was indicated that the efficiency of SDFU assisted enzymolysis was higher than traditional enzymolysis in a limited time. The higher efficiency of SDFU assisted enzymolysis was related with the decrease of E_a and K_M by lowering the energy barrier between ground and active state and increasing affinity between substrate and enzyme.