Browsing by Author "Bouzgarrou, Chaima"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
- Incorporation of tocopherol-rich extracts from mushroom mycelia into yogurtPublication . Bouzgarrou, Chaima; Amara, Khira; Reis, Filipa S.; Barreira, João C.M.; Skhiri, Fethia; Chatti, Noureddine; Martins, Anabela; Barros, Lillian; Ferreira, Isabel C.F.R.Consumers are well-informed about food additives and it is likely that they prefer natural additives over their synthetic analogues. Antioxidants represent a major class of food preservatives, among which tocopherols stand out as one of the most important examples. Interestingly, these compounds are present in relevant amounts in the mycelia of in vitro cultured mushrooms. Accordingly, the mycelia from Ganoderma lucidum, Pleurotus ostreatus and Pleurotus eryngii were used as alternative sources of tocopherols. These extracts were incorporated into different yogurt formulations, which were further compared among each other and with yogurts containing commercial α-tocopherol (E307), regarding their nutritional parameters, fatty acid profile and antioxidant activity. The proposed approach was validated as an effective functionalization strategy, particularly in the case of the G. lucidum mycelium, which showed the highest antioxidant potential, most likely as a result of its tocopherol profile. Furthermore, yogurts prepared with each mycelium extract allowed maintaining the nutritional properties observed in the “blank” yogurt formulation.
- Pleurotus species as a source of bio-preservativesPublication . Bouzgarrou, Chaima; Reis, Filipa S.; Barros, Lillian; Chatti, Noureddine; Ferreira, Isabel C.F.R.; Martins, AnabelaMushrooms are consumed worldwide not only as a part of the normal diet, but also as a delicacy due to their highly desirable taste and aroma. In addition to their nutritional value, mushrooms have been considered functional foods [1] and even as adjuvants in some therapies, namely chemotherapy [2]. This is because they are natural matrices rich in bioactive molecules, such as phenolic compounds, tocopherols, ascorbic acid, or carotenoids. In particular, tocopherols are powerful antioxidants that can be explored as natural food preservatives, in order to replace the widely used synthetic counterparts. With these aspects in mind, and given the evidence that the in vitro culture of mushrooms promotes the production of tocopherols [3], the present work aimed to sub-culture two different mushroom species by in vitro techniques, in order to enhance the production of tocopherols, and use the mycelium as sources of preservative ingredients for foodstuff. The species chosen for the study were two of the most consumed species worldwide, Pleurotus ostreatus (Jacq. ex Fr.) P. Kumm. and Pleurotus eryngii (DC.) Quél. Firstly, both mushroom species were cultivated in different culture media (i.e., MMN complete, MMN incomplete and PDA), in order to optimize the ideal growth conditions. Since the best growth was obtained on PDA medium, both species were cultivated in PDB liquid medium, in order to obtain the amount of biomass required for the assays. After a period of approximately five weeks, the mycelia were recovered, freeze-dried and stored until further analyses. The tocopherols content was evaluated by high performance liquid chromatography coupled with a fluorescence detector. A formulation enriched in tocopherols will be prepared by extraction from the mycelium and further incorporated in cakes. Its preservative capacity will be assessed, through the evaluation of the antioxidant and antimicrobial properties before and after incorporation in the foodstuff. The results will be compared with commercial available and used preservatives (i.e., ascorbic acid- natural antioxidant and potassium sorbate- synthetic preservative).
- Pleurotus species as a source of natural preservatives: mycelia production to obtain tocopherols used as antioxidants in yogurtsPublication . Bouzgarrou, Chaima; Ferreira, Isabel C.F.R.; Martins, Anabela; Chatti, NoureddineMushrooms are consumed worldwide not only as a part of the normal diet, but also as a delicacy due to their highly desirable taste and aroma. In addition to their nutritional value, mushrooms have been considered functional foods and even as adjuvants in some therapies, namely chemotherapy, because they are rich in bioactive molecules, such as phenolic compounds, tocopherols, ascorbic acid, or carotenoids. In particular, tocopherols are powerful antioxidants that can be explored as natural food preservatives, in order to replace the widely used synthetic counterparts. With these aspects in mind, and given the evidence that the in vitro culture of mushroom mycelia promotes the production of tocopherols, the present work aimed to sub-culture two edible species, Pleurotus ostreatus (Jacq. ex Fr.) P. Kumm. and Pleurotus eryngii (DC.) Quél., in different culture media (i.e., Melin–Norkans medium, MMN; modified Melin–Norkans medium, MMNm; and Potato dextrose agar medium, PDA) in order to enhance the production of tocopherols, and use the mycelia as sources of preservative ingredients for foodstuff. Since the best growth was obtained on PDA medium, both species were cultivated in Potato dextrose broth liquid medium (PDB), in order to obtain the amount of biomass required for the assays. The tocopherols content was evaluated by high performance liquid chromatography coupled to a fluorescence detector (HPLC-fluorescence). A formulation enriched in tocopherols was incorporated in yogurts and its preservative capacity was assessed, through the evaluation of the antioxidant properties before and after incorporation in the foodstuff. The results were compared with commercial available and used preservatives (i.e., α-tocopherol - natural antioxidant (E307) and potassium sorbate - synthetic preservative (E202)). The results showed that the mycelium content of tocopherols was particularly high in β-tocopherol and, in the case of P. ostreatus, it was higher than in P. eryngii. Despite the similarity showed in the tocopherol profile for both mushrooms, P. ostreatus mycelium revealed a slightly high DPPH radical scavenging activity, while P. eryngii showed higher reducing power. The DPPH radical scavenging activity measured in yogurts fortified with P. ostreatus and P. eryngii extracts was similar to that achieved in yogurts prepared with potassium sorbate, despite not as strong as yogurts with α-tocopherol. Regarding the reducing Pleurotus species as a source of natural preservatives Abstract VIII power, yogurts with Pleurotus species extracts revealed approximate results of those obtained in yogurts with α-tocopherol, reaching best results than those obtained in yogurts containing potassium sorbate. In neither case were observed significant changes induced by the storage time.