Changes Induced by Pressure Processing on Immunoreactive Proteins of Tree Nuts

Tree nuts confer many health benefits due to their high content of vitamins and antioxidants, and they are increasingly consumed in the last few years. Food processing is an important industrial tool to modify allergenic properties of foods, in addition to ensuring safety and enhancing organoleptic characteristics. The effect of high pressure, without and with heating, on SDS-PAGE and immunodetection profile of potential allergenic proteins (anti-11S, anti-2S and anti-LTP) of pistachio, cashew, peanut, hazelnut, almond, and chestnut was investigated. Processing based on heat and/or pressure and ultra-high pressure (HHP, 300–600 MPa) without heating was applied. After treating the six tree nuts with pressure combined with heat, a progressive diminution of proteins with potential allergenic properties was observed. Moreover, some tree nuts proteins (pistachio, cashew, and peanut) seemed to be more resistant to technological processing than others (hazelnut and chestnut). High pressure combined with heating processing markedly reduce tree nut allergenic potential as the pressure and treatment time increases. HHP do not alter hazelnut and almond immunoreactivity.

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The Reactivity and Allergenic Potential of Hazelnut Peptides

Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca Food Science and Technology ◽

10.15835/buasvmcn-fst:9506 ◽

2013 ◽

Vol 70 (1) ◽

pp. 25

Author(s):

Lavinia Florina Calinoiu ◽

Dan Cristian Vodnar ◽

Carmen Socaciu

Keyword(s):

Proteolytic Enzymes ◽

Peptide Fragments ◽

Dot Blot ◽

Specific Antibodies ◽

Allergenic Potential ◽

Sds Page ◽

Allergenic Proteins ◽

Life Threatening ◽

Specific Proteins ◽

Sensitive Method

The aim of this paper was to focus on proteins present in some food products, like hazelnuts and to investigate their allergenic potential. Several techniques were used to characterize these extracted proteins, with respect to their composition, degradability by digestive proteolytic enzymes and their reactivity with specific antibodies. It was important to analyse which proteins were present in the hazelnuts, to see if there were proteins present to trigger an allergic reaction and if the digestion enzymes trypsin and pepsin influence the presence of the (allergic) protein compounds. Allergies to tree nuts and seeds can cause life-threatening and sometimes fatal reactions. To examine the properties of Hazelnut protein it was important to solubilize it by extraction. After extraction, it was investigated how hazelnut protein can be modified by proteases and what the effect was on the immune reaction. The Bradford method is a fast and sensitive method to determine the concentration of soluble protein. When the Bradford reagent (Coomassie Brilliant Blue) binds to the protein, the colour changes from red to purple and the absorption maximum changes from 495 to 595 nm. The value obtained as the final concentration of proteins was 7.3495. SDS-PAGE is a method to separate mixtures of proteins by electrophoresis. Protein molecules are negatively charged by binding of SDS molecules; subsequently they are separated in an electric field. Their differences in size (molecular weight) leads to separation. In this case the method is used to follow proteolytic degradation of hazelnut proteins (allergens) by intestinal proteases (trypsin, pepsin). A different, more specific and sensitive method is immunoblotting (Western Blot) in which the SDS-PAGE separated proteins are transferred from the gel to a membrane and specific antibodies are used in a series of reactions to visualize specific allergens on this membrane. The remarked spots represented a positive identification of allergenic proteins. This means that peptide fragments of various size, produced during the digestion of a protein can still be immunological active. As it was shown there was still reactivity between proteins and specific antibodies. The Dot Blot is a simple immunoblotting technique used to detected specific proteins in a mixture of different proteins and/or other molecules. No separation technique prior to the actual immuno-detection is necessary. Also, Dot Blot confirmed the presence of allergenic proteins made visible through the light spots on the membrane.

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Influence of Instant Controlled Pressure Drop (DIC) on Allergenic Potential of Tree Nuts

10.20944/preprints202002.0204.v1 ◽

2020 ◽

Author(s):

Fatima Vicente ◽

Africa Sanchiz ◽

Rosa Rodriguez ◽

Maria Pedrosa ◽

Santiago Quirce ◽

...

Keyword(s):

Pressure Drop ◽

Conformational Changes ◽

Electrophoretic Pattern ◽

Temperature Treatment ◽

Western Blots ◽

Tree Nuts ◽

Allergenic Potential ◽

Allergenic Proteins ◽

Instant Controlled Pressure Drop ◽

Suitable Technique

Pistachio and cashew contain allergenic proteins, which causes them to be removed from the diet of allergic people. Former evidences have demonstrated that food processing (thermal and non-thermal) can produce structural and/or conformational changes in proteins by altering their allergenic capacity. In this study, the influence of Instant Controlled Pressure Drop (DIC) on the pistachio and cashew allergenic capacity has been studied. Western blot was carried out using IgG anti-11S and anti-2S and IgE antibodies from sera of patients sensitized to pistachio and cashew. DIC processing causes changes in the electrophoretic pattern, reducing the number and intensity of protein bands, as the pressure and temperature treatment increment what results in a remarkable decrease of detection of potentially allergenic proteins. The harshest conditions of DIC (7bar, 120s) markedly reduce the immunodetection of allergenic proteins, not only by using IgG (anti 11S and anti 2S) but also when IgE sera from sensitized patients were used for Western blots. Such immunodetection is more affected in pistachio than in cashew nuts, but it not completely removed. Therefore, cashew proteins are possibly more resistant than pistachio proteins. According these findings, Instant Controlled Pressure Drop (DIC) can be considered a suitable technique in order to obtain hypoallergenic tree nuts flour to be used in food industry.

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Ultra-High Pressure Chilled Meat Processing: A Promising Storage Method

E3S Web of Conferences ◽

10.1051/e3sconf/202017603022 ◽

2020 ◽

Vol 176 ◽

pp. 03022

Author(s):

Sergei Tikhonov ◽

Natalya Tikhonova ◽

Vladimir Lazarev ◽

Elena Samokhvalova ◽

Leonid Minukhin ◽

...

Keyword(s):

High Pressure ◽

Storage Time ◽

Working Fluid ◽

Customs Union ◽

Refrigerated Storage ◽

Meat Processing ◽

Ultra High Pressure ◽

Organoleptic Characteristics ◽

Positive Effect ◽

Special Working

The positive effect of ultra-high pressure on the shelf life of chilled meat during refrigerated storage has been established. It has been proven that 6 minutes meat processing at the 800 MPa pressure provides high organoleptic characteristics (color, smell, texture), microbiological safety, so KMAFAnM, yeast and other studied parameters do not exceed the requirements of the technical regulation of the Customs Union “On Food Safety” (TR TS 021/2011), prevents the breakdown of protein and does not result into oxidative damage. At that time, samples of chilled meat not processed by pressure, after 60 days of refrigerated storage, corresponded to stale meat according to organoleptic, physiochemical and microbiological indicators. Therefore, the processing of meat, packed in vacuum packaging, helps to increase its storage time. We have calculated the design of equipment for processing meat with high pressure, by comprehensive compression of the working fluid in a special working chamber.

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The Effect of Ultra-High Pressure on the Functional Property and Conformation of Whey Protein Isolated

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.201-203.1008 ◽

2011 ◽

Vol 201-203 ◽

pp. 1008-1014

Author(s):

Hui Ping Liu ◽

Yong Hua Wei ◽

Yi Wen Xu

Keyword(s):

High Pressure ◽

Whey Protein ◽

Functional Properties ◽

Food Processing ◽

Nutritional Value ◽

Treatment Time ◽

New Technology ◽

Applied Pressure ◽

Amino Acid Residues ◽

Ultra High Pressure

The whey protein has a highly nutritional value but poor functional properties. Ultra-high pressure (UHP) is a new technology for food processing. It dose not cause environmental pollution and could maintain food nutrition as much as possible. The effects of applied pressure and treatment time on functional properties and conformation changes of whey protein isolated (WPI) treated by UHP were studied in present paper. The results indicated that WPI treated by UHP showed reduced solubility, foaming and emulsifying property with the increasing of applied pressure and prolonging of treatment time. For WPI treated at 400MPa for 15min, the 1-anilinonaphthalene-8-sulphonate (ANS) studies showed the increasing fluorescence regions when the applied pressure increased. The most fluorescence regions were exposed to aqueous solution for WPI treated at 400MPa for 5min, and degree of exposure reduced when treatment time was prolonged. With the increasing of applied pressure and prolonging of treatment time, the amino acid residues having ultraviolet absorbance showed the same change as hydrophobic group.

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Influence of Instant Controlled Pressure Drop (DIC) on Allergenic Potential of Tree Nuts

10.20944/preprints202002.0204.v2 ◽

2020 ◽

Author(s):

Fatima Vicente ◽

Africa Sanchiz ◽

Rosa Rodriguez-Perez ◽

Maria Pedrosa ◽

Santiago Quirce ◽

...

Keyword(s):

Pressure Drop ◽

Conformational Changes ◽

Electrophoretic Pattern ◽

Temperature Treatment ◽

Western Blots ◽

Tree Nuts ◽

Allergenic Potential ◽

Allergenic Proteins ◽

Instant Controlled Pressure Drop ◽

Suitable Technique

Pistachio and cashew contain allergenic proteins, which causes them to be removed from the diet of allergic people. Former evidences have demonstrated that food processing (thermal and non-thermal) can produce structural and/or conformational changes in proteins by altering their allergenic capacity. In this study, the influence of Instant Controlled Pressure Drop (DIC) on the pistachio and cashew allergenic capacity has been studied. Western blot was carried out using IgG anti-11S and anti-2S and IgE antibodies from sera of patients sensitized to pistachio and cashew. DIC processing causes changes in the electrophoretic pattern, reducing the number and intensity of protein bands, as the pressure and temperature treatment increment what results in a remarkable decrease of detection of potentially allergenic proteins. The harshest conditions of DIC (7bar, 120s) markedly reduce the immunodetection of allergenic proteins, not only by using IgG (anti 11S and anti 2S) but also when IgE sera from sensitized patients were used for Western blots. Such immunodetection is more affected in pistachio than in cashew nuts, but it not completely removed. Therefore, cashew proteins are possibly more resistant than pistachio proteins. According these findings, Instant Controlled Pressure Drop (DIC) can be considered a suitable technique in order to obtain hypoallergenic tree nuts flour to be used in food industry.

Download Full-text