Among legumes, the lentil (Lens culinaris) is a major dietary component in many Mediterranean and Asian countries due to its high nutritional value, especially protein [1]. Italy is the eighth producer of legumes in Europe; however, about 20% of the total legume production is represented by organic waste deriving from the decortication process [2]. The valorization and recycling of these waste materials is particularly interesting in view of the concept of circular economy based on the principle "reduce, reuse, recycle". In this investigation, we focused on two varieties of lentils (Lens Culinaris Medik), namely Eston green (EG) and Crimson red (CR), characterizing whole seeds and their by-product deriving from the decortication industrial process. Indeed, this by-product is rich in bioactive compounds and may be considered an eco-friendly source of health-promoting compounds [3]. The aim of this work was to characterize by high resolution mass spectrometry and advanced bioinformatics tools, the proteomic profile of EG and CR seeds and hulls in order to identify specific hulls proteins and potential differences between the two varieties, in the perspective to disclose potentiality as well as pitfalls of hulls reuse in derived commodities. Seeds and hulls samples were extracted with denaturing buffer and subjected to 16h trypsin digestion after proper denaturation, reduction and alkylation steps. The LC-MS/MS analysis were carried out according to well established conditions for discovery analysis [5]. The raw data were processed by Proteome Discoverer v.3.0.1.27 (Thermo Fisher Scientific) for peptide/protein identification against a customized database restricted to Fabaceae taxonomy. Protein list was elaborated for protein classification according to their family/putative function. Most proteins have been identified and classified into 13 categories endowed with specific functions and properties: storage proteins, enzymes, Heat Shock Proteins, LEA Proteins, annexins, actins and others. From a qualitative point of view, these protein classes are common to the two varieties. From a quantitative point of view, the predominant class for the lentil hulls was the storage proteins (80%-85%): cupin (11S-legumins and 7S-vicilins) and prolamins (albumins and non-specific LTP). Confirmed and potential lentil allergens were identified according to official databases and very recent literature [1]. For both varieties, the most common allergens were Len c 1.0101, Convicillin and Len c 1.0102, well-known lentil allergens present in all plant allergen databases. As demonstrated, although lentil hulls are rich in beneficial compounds, the persistence of main allergenic proteins typical of seed cotyledons, raised safety concerns and requires proper attention by food manufacturer in case of reuse in derived commodities.
Protein profiling and varietal comparison of lentils seeds and hulls by discovery proteomics
R Pilolli;E De Angelis;L Monaci
2023
Abstract
Among legumes, the lentil (Lens culinaris) is a major dietary component in many Mediterranean and Asian countries due to its high nutritional value, especially protein [1]. Italy is the eighth producer of legumes in Europe; however, about 20% of the total legume production is represented by organic waste deriving from the decortication process [2]. The valorization and recycling of these waste materials is particularly interesting in view of the concept of circular economy based on the principle "reduce, reuse, recycle". In this investigation, we focused on two varieties of lentils (Lens Culinaris Medik), namely Eston green (EG) and Crimson red (CR), characterizing whole seeds and their by-product deriving from the decortication industrial process. Indeed, this by-product is rich in bioactive compounds and may be considered an eco-friendly source of health-promoting compounds [3]. The aim of this work was to characterize by high resolution mass spectrometry and advanced bioinformatics tools, the proteomic profile of EG and CR seeds and hulls in order to identify specific hulls proteins and potential differences between the two varieties, in the perspective to disclose potentiality as well as pitfalls of hulls reuse in derived commodities. Seeds and hulls samples were extracted with denaturing buffer and subjected to 16h trypsin digestion after proper denaturation, reduction and alkylation steps. The LC-MS/MS analysis were carried out according to well established conditions for discovery analysis [5]. The raw data were processed by Proteome Discoverer v.3.0.1.27 (Thermo Fisher Scientific) for peptide/protein identification against a customized database restricted to Fabaceae taxonomy. Protein list was elaborated for protein classification according to their family/putative function. Most proteins have been identified and classified into 13 categories endowed with specific functions and properties: storage proteins, enzymes, Heat Shock Proteins, LEA Proteins, annexins, actins and others. From a qualitative point of view, these protein classes are common to the two varieties. From a quantitative point of view, the predominant class for the lentil hulls was the storage proteins (80%-85%): cupin (11S-legumins and 7S-vicilins) and prolamins (albumins and non-specific LTP). Confirmed and potential lentil allergens were identified according to official databases and very recent literature [1]. For both varieties, the most common allergens were Len c 1.0101, Convicillin and Len c 1.0102, well-known lentil allergens present in all plant allergen databases. As demonstrated, although lentil hulls are rich in beneficial compounds, the persistence of main allergenic proteins typical of seed cotyledons, raised safety concerns and requires proper attention by food manufacturer in case of reuse in derived commodities.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
