Agri-food waste, originating throughout the whole food supply chain, represents an urgent issue from an economic, environmental and social point of view. Long simplistically defined as uneaten edible food, it is still considered an underutilized resource and a key sustainability issue. In this framework, in recent years, great attention has been paid to the exploitation of wastes and by-products for the production of value-added products, offering a great opportunity to address their conventional management which is of great interest in the food, cosmetic and pharmaceutical fields.1 Among the most studied compounds in waste, phenols are highly recognised for their potential bioactivity ranging from radical scavenging to antioxidant, antibacterial, and antiinflammatory properties in addition to other health benefits. Therefore, alternative pathways to the production of e.g. renewable energy or animal feeds, include the valorization of waste as a source of bioactives, such as phenolic compounds, to be used as functional ingredients or nutraceuticals.1 Due to the high complexity of waste products and structural variability of naturally occurring phenols, different molecules are simultaneously extracted, many of which are still pending identification. Moreover, beyond the enormous structural diversities, phenolic compounds can exist as glycosides or aglycones, are often extracted bound to other matrix components, and can be affected by low stability. For these reasons, advances in the extraction, purification, and characterization of phenols still pose several challenges, which require in-depth investigation and method development. In this work, simple analytical workflows to characterize the phenolic fraction from grape pomace and potato sprouts are presented. The non-conventional ultrasound-assisted extraction (UAE) technique was optimized through the set-up of an experimental design to allow for the selection of the most influential parameters. Concerning grape pomace extracts, a post-extraction treatment by chemical and enzymatic hydrolysis was also evaluated to simplify subsequent chromatographic data. The effectiveness of anti-browning acid additives in controlling the enzymatic browning reaction was, instead, investigated for the extraction of bioactives from potato sprouts.2 In both studies, an optimized HPLC-DAD method was developed for qualitative profile monitoring and quantitative analysis of identified phenols. The in vitro total antioxidant capacity was measured to evaluate the potential bioactivity of the final extracts. As the last step, the accurate characterization of the extracts could not overlook a final investigation by LC-MS, as the technique of choice for the unambiguous identification of target compounds and structural elucidation of unknown molecules in support of HPLC-DAD analyses.
Method development and LC-MS-aided investigations for the characterization of phenols from agri-food waste
Federica Ianni;Francesca Blasi;Luciano Mangiapelo;Lina Cossignani
2023
Abstract
Agri-food waste, originating throughout the whole food supply chain, represents an urgent issue from an economic, environmental and social point of view. Long simplistically defined as uneaten edible food, it is still considered an underutilized resource and a key sustainability issue. In this framework, in recent years, great attention has been paid to the exploitation of wastes and by-products for the production of value-added products, offering a great opportunity to address their conventional management which is of great interest in the food, cosmetic and pharmaceutical fields.1 Among the most studied compounds in waste, phenols are highly recognised for their potential bioactivity ranging from radical scavenging to antioxidant, antibacterial, and antiinflammatory properties in addition to other health benefits. Therefore, alternative pathways to the production of e.g. renewable energy or animal feeds, include the valorization of waste as a source of bioactives, such as phenolic compounds, to be used as functional ingredients or nutraceuticals.1 Due to the high complexity of waste products and structural variability of naturally occurring phenols, different molecules are simultaneously extracted, many of which are still pending identification. Moreover, beyond the enormous structural diversities, phenolic compounds can exist as glycosides or aglycones, are often extracted bound to other matrix components, and can be affected by low stability. For these reasons, advances in the extraction, purification, and characterization of phenols still pose several challenges, which require in-depth investigation and method development. In this work, simple analytical workflows to characterize the phenolic fraction from grape pomace and potato sprouts are presented. The non-conventional ultrasound-assisted extraction (UAE) technique was optimized through the set-up of an experimental design to allow for the selection of the most influential parameters. Concerning grape pomace extracts, a post-extraction treatment by chemical and enzymatic hydrolysis was also evaluated to simplify subsequent chromatographic data. The effectiveness of anti-browning acid additives in controlling the enzymatic browning reaction was, instead, investigated for the extraction of bioactives from potato sprouts.2 In both studies, an optimized HPLC-DAD method was developed for qualitative profile monitoring and quantitative analysis of identified phenols. The in vitro total antioxidant capacity was measured to evaluate the potential bioactivity of the final extracts. As the last step, the accurate characterization of the extracts could not overlook a final investigation by LC-MS, as the technique of choice for the unambiguous identification of target compounds and structural elucidation of unknown molecules in support of HPLC-DAD analyses.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
