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

The Free-Amino-Acid Content in Six Potatoes Cultivars through Storage

Potatoes of six cultivars (Solanum tuberosum L.) with red, purple, and yellow flesh were stored at 2 and 5 °C for 3 and 6 months, and the influence of these factors on the content of free amino acids was determined. The potato cultivar and storage time had the greatest impact on the free amino acid content. The tubers of red-fleshed (Rote Emma) and purple-fleshed (Blue Congo) potatoes contained over 28 mg/g DM of free amino acids, and the Blaue Annelise cultivar with purple flesh had over 18 mg/g DM. After 6 months, the highest increase in their content (by 36%) was recorded in tubers of the Fresco cultivar (yellow-fleshed). In the analysed potatoes, the content of alanine, proline, serine, γ-aminobutyric acid, and α-aminoadipic acid increased, while that of asparagine, aspartic acid, and glutamine decreased. Asparagine decreased to the greatest extent in “Blaue Annelise” potatoes (by 24%) and that of glutamine in tubers of Rote Emma and Vineta by 18%

Effect of Acetylation on Physicochemical and Functional Properties of Commercial Pumpkin Protein Concentrate

The purpose of the present study was to determine the effects of acetylation with different doses of acetic anhydride on the chemical composition and chosen functional properties of commercial pumpkin protein concentrate (PPC). The total protein content decreased as compared to unmodified samples. Electrophoretic analysis revealed that in the acetylated pumpkin protein, the content of the heaviest protein (35 kDa) decreased in line with increasing concentrations of modifying reagent. Acetylation of PPC caused a significant increase in water-binding and oil-absorption capacity and for emulsifying properties even at the dose of 0.4 mL/g. Additionally, an increase in foaming capacity was demonstrated for preparations obtained with 2.0 mL/g of acetic anhydride, whereas acetylation with 0.4 and 1.0 mL/g caused a decrease in protein solubility as compared to native PPC

Comparative Evaluation of the Antioxidative and Antimicrobial Nutritive Properties and Potential Bioaccessibility of Plant Seeds and Algae Rich in Protein and Polyphenolic Compounds

Spice plants are not only a source of nutrition compounds but also supply secondary plant metabolites, such as polyphenols. Therefore, their bioaccessibility is an important issue. In order to understand the biological activity of polyphenols present in spice plants, it is necessary to broaden knowledge about the factors influencing their bioaccessibility, including nutritional factors. Therefore, the objective of this research was to determine the antioxidative and antimicrobial nutritive properties and potential bioaccessibility of plant seeds and microalgae rich in protein and polyphenolic compounds. Plant seeds rich in protein—i.e., black cumin, milk thistle, fenugreek, almonds, white sesame, white mustard, eggfruit and the two most popular algae, chlorella and spirulina—were analyzed for total polyphenolic compounds (TPC) and antioxidant properties (ABTS, FRAP), as well as their potential bioaccessibility, antimicrobial activity, basic chemical composition and amino acid profiles. With regard to the TPC, the highest levels were found in star anise, followed by milk thistle, white mustard and fenugreek, whereas the lowest were noted in white sesame, almonds, eggfruit, spirulina and chlorella. White mustard and milk thistle showed the highest antioxidant capacities and almonds, eggfruit, spirulina, and chlorella the lowest according to the ABTS and FRAP assays. The widest spectrum of microbial growth inhibition was detected for fenugreek extract, which showed antimicrobial activity against four analyzed microorganisms: B. subtilis, P. mirabilis, V. harveyi and C. albicans. The protein from seeds of black cumin, milk thistle, white mustard and eggfruit and chlorella was not limited by any essential amino acids. Among all analyzed plants, fenugreek seeds were judged to have potential for use in food formulation operations in view of their antioxidant activity and amino acid profile. Based on the results, intake of polyphenols together with protein in plant seeds does not have a major impact on the potential bioaccessibility of a range of polyphenols and phenolic metabolites

Wodochłonność i olejochłonnosc acetylowanych preparatów białka ziemniaczanego

Vytauto Didžiojo universitetasŽemės ūkio akademij

THE QUALITY OF FRIED SNACKS FORTIFIED WITH FIBER AND PROTEIN SUPPLEMENTS

<div style="mso-element: frame; mso-element-frame-width: 498.1pt; mso-element-frame-height: 199.95pt; mso-element-frame-vspace: 3.1pt; mso-element-wrap: around; mso-element-anchor-vertical: page; mso-element-anchor-horizontal: page; mso-element-left: 52.45pt; mso-element-top: 55.2pt; mso-height-rule: exactly;"><table style="height: 275px;" border="0" cellspacing="0" cellpadding="0" width="664" align="left"><tbody><tr><td style="padding-top: 3.1pt; padding-right: 0cm; padding-bottom: 3.1pt; padding-left: 0cm;" height="275" align="left" valign="top"><div style="mso-element: para-border-div; border: none; border-bottom: solid windowtext 2.25pt; padding: 0cm 0cm 1.0pt 0cm;"><p class="MsoNormal" style="text-align: justify; border: none; mso-border-bottom-alt: solid windowtext 2.25pt; padding: 0cm; mso-padding-alt: 0cm 0cm 1.0pt 0cm; mso-element: frame; mso-element-frame-width: 498.1pt; mso-element-frame-height: 199.95pt; mso-element-frame-vspace: 3.1pt; mso-element-wrap: around; mso-element-anchor-vertical: page; mso-element-anchor-horizontal: page; mso-element-left: 52.45pt; mso-element-top: 55.2pt; mso-height-rule: exactly;"><span style="font-size: 10.0pt; mso-bidi-font-weight: bold;">There was studied the effect of fortification of extruded potato pellets, obtained with 5 and 10 % addition of wheat bran, corn bran and corn germ, applied separately and in mixtures with 3 % addition of potato protein concentrate on fat content and physical properties of snacks fried from them. The addition of wheat bran, regardless its dose, did positively influenced on snacks texture. Yet it also caused the increase in fat content and density, as well as darkening of snacks color. The use of corn bran contributed to lower values of snacks density and fat absorption, while the addition of corn germ resulted in lighter, more desired snacks color, but at the same time it brought about increased fat content and made snacks harder. There was not recorded any significant snacks diversity concerning expansion degree, regardless the kind of additive used, as well as snacks moisture.</span></p><p class="MsoNormal" style="text-align: justify; border: none; mso-border-bottom-alt: solid windowtext 2.25pt; padding: 0cm; mso-padding-alt: 0cm 0cm 1.0pt 0cm; mso-element: frame; mso-element-frame-width: 498.1pt; mso-element-frame-height: 199.95pt; mso-element-frame-vspace: 3.1pt; mso-element-wrap: around; mso-element-anchor-vertical: page; mso-element-anchor-horizontal: page; mso-element-left: 52.45pt; mso-element-top: 55.2pt; mso-height-rule: exactly;">&nbsp;</p><p class="MsoNormal" style="text-align: justify; border: none; mso-border-bottom-alt: solid windowtext 2.25pt; padding: 0cm; mso-padding-alt: 0cm 0cm 1.0pt 0cm; mso-element: frame; mso-element-frame-width: 498.1pt; mso-element-frame-height: 199.95pt; mso-element-frame-vspace: 3.1pt; mso-element-wrap: around; mso-element-anchor-vertical: page; mso-element-anchor-horizontal: page; mso-element-left: 52.45pt; mso-element-top: 55.2pt; mso-height-rule: exactly;"><span style="font-size: 10.0pt; mso-bidi-font-weight: bold;"><span style="font-size: 12px;"><strong>doi:10.5219/54</strong></span></span></p></div></td></tr></tbody></table></div

The Functional and Physicochemical Properties of Rice Protein Concentrate Subjected to Acetylation

The aim of the present study was to increase the value of rice protein concentrate (RPC) by improving the functional properties of a preparation subjected to acetylation and analyze the impact of this chemical modification on chemical composition, digestibility, and protein patterning using SDS-PAGE electrophoresis and FT-IR spectroscopy. In the modified samples, the protein content increased (80.90–83.10 g/100 g cf. 74.20 g/100 g in the control). Electrophoresis revealed that the content of the main rice protein fractions (prolamin and glutelin) decreased as the concentration of the modifying reagent increased. Through spectroscopic analysis, wavenumbers, corresponding to the presence of proteins or lipids, aromatic systems, and carbohydrates, were observed. The use of acetic anhydride did not change the digestibility of the modified RPC significantly when compared to that of the control sample. The acetylation of the RPC caused a significant increase in its emulsifying properties at pH 8 (1.83–14.74%) and its water-binding capacity but did not have a statistically significant impact on the oil-absorption capacity. There was a slight increase in protein solubility and a decrease in foaming capacity in the modified RPC

Assessment of the Content of Glycoalkaloids in Potato Snacks Made from Colored Potatoes, Resulting from the Action of Organic Acids and Thermal Processing

Glycoalkaloids (TGAs, total glycoalkaloids), toxic secondary metabolites, are found in potatoes (110–335 mg·kg−1 DW), mainly in the peel. Colorful, unpeeled potatoes are an innovative raw material for the production of snacks which are poorly tested in terms of their glycoalkaloid content. Third-generation snacks and French fries made from red-fleshed Mulberry Beauty (MB) and purple-fleshed Double Fun (DF) potatoes were produced with the use of 1% solutions of ascorbic, citric, lactic, malic, and tartaric acids to stabilize the structure of anthocyanins in the raw material and maintain their color in obtained products. The influence of the type of acid and thermal processes, like frying, microwaving, and baking, on the content of glycoalkaloids in ready-made products was examined. Only 0.45–1.26 mg·100 g−1 of TGA was found in pellet snacks and 1.32–1.71 mg·100 g−1 in French fries. Soaking blanched potatoes in organic acid solution reduced the α-chaconine content by 91–97% in snacks and by 57–93% in French fries in relation to the raw material to the greatest extent after the use of malic acid and the DF variety. The effect of lactic and citric acid was also beneficial, especially in the production of baked French fries from MB potatoes

The comparison of amino acid composition of the protein in preparations obtained from potato tubers cultivated within ecological and conventional systems

Celem przeprowadzonych badań było określenie wpływu termicznej koagulacji białek w soku ziemniaczanym uzyskanym z bulw trzech odmian ziemniaka uprawianych systemem konwencjonalnym i ekologicznym na skład aminokwasowy i wartość odżywczą uzyskanych koncentratów białkowych. W uprawie ziemniaka systemem ekologicznym stosowano użyźniacz glebowy i fungicyd, miedzian 50 WP, a w uprawie systemem konwencjonalnym nawożenie wysokimi dawkami NPK, herbicydy, insektycydy i fungicydy. Koagulację białka w soku przeprowadzono z udziałem CaCl2. Oznaczono skład chemiczny otrzymanych preparatów oraz zawartość 18 aminokwasów w białku ogółem, po uprzedniej hydrolizie białka, przy użyciu automatycznego analizatora aminokwasów. Koncentraty białkowe otrzymane z bulw uprawianych systemem ekologicznym zawierały więcej związków azotowych, w tym form azotu białkowego niż preparaty uzyskane z soku bulw pochodzących z uprawy konwencjonalnej. Również w składzie aminokwasowym wyodrębnionych białek stwierdzono więcej takich aminokwasów egzogennych, jak: leucyna, fenyloalanina i tyrozyna oraz treonina, a wśród pozostałych aminokwasów więcej kwasu asparaginowego, seryny i glicyny. Wskaźnik wartości odżywczej CS badanych koncentratów, w zależności od przyjętego białka wzorcowego był zbliżony lub przewyższał wartości przewidziane dla standardu, szczególnie gdy preparaty pochodziły z surowca uprawianego systemem ekologicznym.The aim of the experiment was to study the influence of thermal coagulation of protein in potato juice isolated from tubers of three potato varieties cultivated conventionally and in ecological system on amino acid composition and nutritive value of obtained preparations. A soil fertilizer and copper salt 50 WP as a fungicide were used within ecological system of potato cultivation and in conventional system fertilizing with high doses of NPK, herbicides, insecticides and fungicides were applied. Protein coagulation was performed in juice containing dissolved CaCl2. After suitable hydrolysis of the obtained concentrates, the chemical composition and contents of 18 amino acids were determined in total protein with the use of automatic amino acid analyser. Potato protein concentrates (PPC) obtained from tubers cultivated within ecological system contained more nitrogen compounds and also forms of protein nitrogen than there were found in preparations originating from juice of tubers cultivated conventionally. Also, in amino acid composition of isolated protein we found more such essential amino acids as Leucine, Phenylalanine, Tyrosine and Threonine. Among remaining amino acids in PPC originating from potatoes cultivated within ecological system there was more of Asparagine acid, Serine and Glycine. Chemical Score (CS) expressing nutritive value of studied concentrates, in dependence of protein standard chosen for comparison occurred similar or higher than it was established for standard, particularly in the case of preparations obtained from tubers cultivated within ecological system

Frankfurter-Type Sausage Enriched with Buckwheat By-Product as a Source of Bioactive Compounds

Buckwheat by-products may be used as promising food ingredients due to their nutritional composition. Buckwheat husk (BH) may be used in meat products as a source of valuable compounds. In this study, the addition of BH to the quality of frankfurter-type sausages was investigated, aiming to reduce buckwheat waste and to develop nutritionally enriched sausages. For the purpose of this study, a range of measurements, as well as observations, have been carried out. This included the following: pH, weight losses, yield, the instrumental color and texture measurement, protein digestibility, polyphenols, amino acid, trace elements analysis, and the organoleptic evaluation. Compared with no BH sausages, the cooking losses of sausages with 3% BH were higher, while storage losses were lower. BH increased the hardness of sausages after two weeks of storage. The growing addition of BH resulted in a decrease in L* and b*. This change of color resulted in its lower level of consumer acceptability. BH addition did not reduce the protein digestibility. The total amino acid content increased with the increasing husk addition, from 161.8 mg/kg to 228.0 mg/kg. Moreover, BH increased the content of manganese, calcium, potassium and magnesium. This research suggested that incorporation of BH improved the nutritional value of sausages with minimal changes in technological and sensory properties