Oil Structuring for Improving Healthy and Sustainable Diets: The Case Study of Extra Virgin Olive Oil Oleogelation

The aim of this PhD research project is to develop novel and sustainable strategies to structure liquid oils into pseudoplastic materials, called oleogels, to be used as saturated fat substitutes or as functional components able to modulate lipolysis during human digestion as well as deliver bioactive lipophilic molecules. In this context, the use of extra virgin olive oil (EVOO) as a target oil to be gelled would be particularly interesting due to its well- recognized health-promoting capacity. In this case study, EVOO-based oleogels were developed by using different gelation strategies. The oleogels, after structural characterization, were in vitro digested to study the impact of oil structure on the free fatty acids (FFA) release and polyphenols’ bioaccessibility. 1. Introduction In accordance with the PhD thesis project previously described (Ciuffarin, 2021), this poster reports the main results of the following activities: (A1) Study of strategies for oil structuring (e.g., methods and selection of gelators). (A3) Evaluation of the effect of oleogelation on the gastrointestinal behavior of oleogels by determining the bioaccessibility of selected bioactive molecules (e.g., polyphenols) as well as the lipolysis degree by using in vitro digestion methodologies. 2. Materials and Methods Oleogels were obtained by adding 10 % (w/w) of saturated monoglycerides (MG), rice bran waxes (RW), sunflower waxes (SW), and β-sitosterol/γ-oryzanol mixture (PS) in EVOO heated at temperatures higher than the melting temperatures of the different gelators. Additionally, a whey protein-based oleogel (WP) was prepared by mixing EVOO with a WP aerogel prepared following the methodology of Plazzotta et al. (2020). The final oil content in WP-based oleogels was 80% (w/w). Oleogels were characterized for their structure using a texture analyzer (35 mm-diameter cylindrical probe for 5 mm of distance at a crosshead speed of 1.5 mm/s, TA. XT Plus, Stable Micro Systems Ltd, Godalming, UK) and an accelerated release test by centrifuging samples (10000g for 15 min, Mikro 120, Hettich Zentrifugen, Andreas Hettich GmbH and Co, Tuttlingen, Germany). Unstructured EVOO and oleogels were then subjected to in vitro digestion according to the protocol proposed by Brodkorb et al. (2019). The FFAs released during digestion were assessed by titration (pH-stat). The bioaccessibility of tyrosol (T) and hydroxytyrosol (HT) was evaluated as the percentage ratio between the concentration of these components included in the micellar phase after intestinal in vitro digestion and their concentration in the undigested sample. The polyphenols were determined by HPLC. 3. Results and Discussion 3.1 Oleogel physical properties Table 1 shows the oil retention capacity and firmness of the considered oleogels. All the samples presented a very high oil retention capacity upon centrifugation (<99%) despite the different firmness. The MG-based oleogel was the weakest gel, followed by WP, RW, SW, and PS. These mechanical properties can be associated with the different natures of the networks structuring EVOO. In agreement with the literature, MG, RW, and SW formed a crystalline network (da Pieve et al., 2010; Doan et al., 2015), PS generated a fibrillar structure (Scharfe et al., 2019) and protein aerogels absorbed oil in the protein porous structure (Plazzotta et al., 2021). 3.2 In-vitro digestion: FFA release and bioaccessibility Figure 1 shows the FFA release as a function of the digestion time of structured into oleogels and unstructured EVOO. The typical curve of lipid hydrolysis was obtained. The unstructured oil presented FFA release % of about 68%, followed by PS, SW, RW, and MG with 59.1, 50.8, 50.7, and 42.8% respectively. A different behavior was acquired for WP- based oleogels showing the complete digestion of the oil. These results clearly show that the extent of lipid lipolysis was significantly affected by oil structure. In the case of liposoluble gelators (i.e., MG, RW, SW, PS), it can be inferred that the lipase activity was hindered by the presence of a structuring network behaving like a physical barrier to the access of the enzyme to the substrate sites. On the contrary, WP probably completely dissolved in the gastrointestinal environment thus favouring the emulsification of the oil and thus the lipase activity. In summary, the results demonstrated that the digestibility of the oil can be steered by selecting the proper oleogelator. In the next part of the study, the bioaccessibility of the major EVOO polyphenols (i.e., tyrosol and hydroxytyrosol) was assessed. Despite the higher content of hydroxytyrosol (HT) in EVOO than tyrosol (T) (HT: 248 mg/kg, T: 96 mg/kg), the bioaccessibility of T was significantly higher than that of HT. This result can be explained by considering the different susceptibility to oxidation of the two molecules during digestion (Alberdi-Cedeño et al., 2020). Moreover, differences were recorded among oleogels. Unstructured oil and WP presented the higher T bioaccessibility values, followed by SW, MG and RW, and PS. Since it is impossible to observe a direct effect of gel strength on polyphenol bioaccessibility, it can be speculated a possible interaction between the polyphenols and oleogel network structures. In fact, as well-known, polyphenols are surface-active molecules with the potentiality to interact with other food components. In conclusion, the results reported in the present study confirm that oleogelation could be a profitable strategy to modulate lipid digestion while delivering bioactive molecules. 4. References Alberdi-Cedeño, J., Ibargoitia, M. L., & Guillén, M. D. (2020). Study of the in vitro digestion of olive oil enriched or not with antioxidant phenolic compounds. Relationships between bioaccessibility of main components of different oils and their composition. Antioxidants, 9(6). Brodkorb, A., Egger, L., Alminger, M., Alvito, P., Assunção, R., Ballance, S., Bohn, T., Bourlieu-Lacanal, C., Boutrou, R., Carrière, F., Clemente, A., Corredig, M., Dupont, D., Dufour, C., Edwards, C., Golding, M., Karakaya, S., Kirkhus, B., le Feunteun, S., ... Recio, I. (2019). INFOGEST static in vitro simulation of gastrointestinal food digestion. Nat. Protoc., 14(4), 991–1014. da Pieve, S., Calligaris, S., Co, E., Nicoli, M. C., & Marangoni, A. G. (2010). Shear Nanostructuring of monoglyceride organogels. Food Biophys., 5(3), 211–217. Doan, C. D., van de Walle, D., Dewettinck, K., & Patel, A. R. (2015). Evaluating the oil-gelling properties of natural waxes in rice bran oil: Rheological, thermal, and microstructural study. JAOCS,92(6). Plazzotta, S., Calligaris, S., & Manzocco, L. (2020). Structural characterization of oleogels from whey protein aerogel particles. Int. Food Res. J., 132, 109099. Plazzotta, S., Jung, I., Schroeter, B., Subrahmanyam, R. P., Smirnova, I., Calligaris, S., Gurikov, P., & Manzocco, L. (2021). Conversion of whey protein aerogel particles into oleogels: Effect of oil type on structural features. Polym. J., 13(23). Scharfe, M., Ahmane, Y., Seilert, J., Keim, J., & Flöter, E. (2019). On the Effect of Minor Oil Components on β- Sitosterol/γ-oryzanol Oleogels. Eur. J. Lipid Sci. Technol., 121(8)

Le acque del Carso classico : Progetto Hydrokarst

Dopo quasi 200 anni dalle prime ricerche sul Timavo, prende il via il Progetto HYDROKARST nato dalle idee di ricercatori italiani e sloveni che da anni studiano insieme l\u2019idrogeologia carsica (www.hydrokarstproject.eu). Il progetto ha come obiettivo la gestione coordinata e la tutela dell\u2019acquifero transfrontaliero del Reka-Timavo attraverso l\u2019istituzionalizzazione di una rete di monitoraggio quantitativo e qualitativo delle acque ipogee e del territorio del Carso Classico. Il progetto si propone di garantire, attraverso delle partnership stabili, una gestione sostenibile della risorsa acqua rafforzando quella coesione territoriale transfrontaliera che deve portare alla redazione di protocolli congiunti per permettere di uniformare le metodologie di raccolta dati e la loro rappresentazione e codifica, primo passo per la definizione delle aree di salvaguardia delle sorgenti e dei pozzi captati a scopo idropotabile. Va ricordato che ad oggi, le acque del Reka-Timavo non sono legalmente tutelate, cosa che invece accade per quelle del fiume Isonzo-So\u10da. Il progetto \ue8 suddiviso in sette diversi Workpakages (WP). WP1: Progettazione e costruzione del quadro logico per la gestione del progetto. Monitoraggio coordinamento e rendicontazioni. WP2: Ideazione, preparazione e definizione dell\u2019idea progettuale. WP3: Raccolta ed elaborazione dei dati idrodinamici, idrochimici e biologici dell\u2019acquifero del Reka-Timavo. WP4: Vulnerabilit\ue0 degli acquiferi carsici e protocolli di individuazione delle aree di salvaguardia. Uso del suolo. Analisi della stabilit\ue0 della rete di distribuzione e delle necessit\ue0 di approvvigionamento idrico. WP5: Elaborazione della cartografia unificata del Carso Classico. WP6: Elaborazione di protocolli per la gestione condivisa delle risorse e delle riserve acquifere del Carso Classico. WP7: Piano di comunicazione. La fase di condivisione dati ha portato alla realizzazione di una base cartografica unificata e di una banca dati georeferenziata (GIS) di tutto il bacino del Carso Classico. Attraverso la raccolta dati prima, e l\u2019elaborazione poi, si \ue8 giunti alla definizione di un modello concettuale dell\u2019intero acquifero del Reka-Timavo. Buona parte di questi dati hanno successivamente permesso l\u2019elaborazione delle carte di vulnerabilit\ue0, a loro volta determinanti per la delimitazione delle aree di salvaguardia. Il monitoraggio della rete acquedottistica di distribuzione e la realizzazione di interventi per il risparmio idrico hanno permesso di promuovere progetti di minimizzazione delle perdite, ottimizzando tratti poco efficienti delle reti. Scopo ultimo del progetto era pertanto l\u2019elaborazione: \u2013 di accordi di cooperazione e di azioni per la promozione ed attuazione di sistemi per la riduzione delle emissioni inquinanti con particolare riferimento all\u2019acqua potabile; \u2013 di sistemi di intervento congiunti nelle situazioni di emergenza; \u2013 di strategie congiunte per prevenire e ridurre i rischi; \u2013 di interventi per il risparmio idrico, l\u2019efficienza nella gestione della rete idrica ed il miglioramento della qualit\ue0 dell\u2019acqua potabile. Skoraj dvesto let po prvih raziskavah reke Timave so italijanski in slovenski raziskovalci, ki \u17ee ve\u10d let skupaj preu\u10dujejo kra\u161ko hidrogeologijo, oblikovali Projekt HYDROKARST (www.hydrokarst-project.eu). Cilj projekta je koordinirano upravljanje in za\u161\u10dita \u10dezmejnega vodonosnika Reka-Timava z institucionalizacijo omre\u17eja za koli\u10dinsko in kakovostno spremljanje podzemnih voda na obmo\u10dju klasi\u10dnega Krasa. Namen projekta je, da se z vzpostavitvijo stalnega partnerstva zagotovi trajnostno upravljanje vodnega vira, \u10dezmejna teritorialna kohezija in priprava skupnih strokovnih podlag, ki bodo omogo\u10dale poenotenje metodologij zbiranja, prikazovanja in kodifikacije podatkov, kar je prvi korak v smeri definicije za\u161\u10ditenih obmo\u10dij izvirov in zajemali\u161\u10d pitne vode. Naj spomnimo, da vse do dana\u161njih dni vodonosnik Reka-Timava ni bil dele\u17een nikakr\u161ne pravne za\u161\u10dite \u2013 v nasprotju na primer s So\u10do (Isonzo). Projekt sestavlja sedem razli\u10dnih delovnih sklopov (WP): WP1: Oblikovanje \u201cstoritvenega sistema\u201d in priprava logi\u10dnega okvira za upravljanje projekta. Spremljanje projekta, koordiniranje in finan\u10dno poro\u10danje. WP2: Oblikovanje, priprava in dolo\u10ditev projektne ideje. WP3: Meritve in obdelava hidrodinami\u10dnih podatkov vodonosnika Reka-Timava. WP4: Ranljivost kra\u161kih vodonosnikov in protokoli za dolo\u10ditev vodovarstvenih obmo\u10dij. Raba tal. Analiza stabilnosti distribucijskegaomre\u17eja in potreb po vodni preskrbi. WP5: Priprava skupnih kartografskih prikazov mati\u10dnega Krasa. WP6: Priprava protokolov za skupno upravljanje virov in zalog mati\u10dnega Krasa. WP7: Komunikacijska kampanja o razvoju projekta in dose\u17eenih ciljih. Faza izmenjave podatkov je omogo\u10dila vzpostavitev enotnih kartografskih podlag in enotne georeferencirane podatkovne baze (GIS) za celotno obmo\u10dje mati\u10dnega Krasa. Z zbiranjem in obdelavo podatkov smo izdelali konceptualni model celotnega vodonosnika Reka-Timava. Ti podatki so nadalje omogo\u10dili izdelavo kart ranljivosti, ki so bistvenega pomena za dolo\u10ditev vodovarstvenih obmo\u10dij. Spremljanje distribucijskega vodovodnega omre\u17eja in izvajanje ukrepov za var\u10devanje z vodo je omogo\u10dilo implementacijo projektov za zmanj\u161anje izgub z izbolj\u161avami na neu\u10dinkovitih delih omre\u17eja. Kon\u10dni cilj projekta je torej: \u2013 sklenitev protokolov o sodelovanju in dolo\u10ditev ukrepov promocije in uresni\u10denja sistemov za zmanj\u161anje onesna\u17eevalnih emisij, predvsem tistih, ki se nana\u161ajo na pitno vodo; \u2013 razvoj sistemov skupnega poseganja v nujnih primerih; \u2013 oblikovanje skupnih strategij za prepre\u10devanje in zmanj\u161evanje tveganj; \u2013 promocija posegov za var\u10devanje z vodo, u\u10dinkovito upravljanje vodovodnega omre\u17eja in izbolj\u161anje kakovosti pitne vode

Estudio sedimentológico preliminar y análisis de minerales pesados en la cueva Pocala

[Abstract] In 1999 two borings were performedin the area of Pocala Cave, one outside the cave and the other inside in the cave. In particular four samples of the first boring were studied.It seems that mineralogy is strictly connected with sedimentology where quartz and plagioclase are present. It could be a consequence of a periodical floods of flysch sediments during interglacial perio

Effects of long term feeding diets differing in protein source and pre-slaughter starvation on biometry, qualitative traits and liver IGF-I expression in large rainbow trout

The effects of feeding two complete extruded diets differing in protein source (fish meal-FM vs. vegetable proteins-VP) over 30 weeks and subsequent 30 days of starvation on biometry, fillet composition and liver IGF-I mRNA were studied in large rainbow trout. At the end of the feeding period, the dietary protein source little affected major biometry traits, dressing out yields and overall adiposity (P>0.05) but fish given the VP diet resulted in higher content of PUFA n-6 fatty acids in mus- cle (0.46 vs. 0.22 g/100g fillet, P0.05) and of all fatty acids in fillet (P<0.05), except DHA. Liver IGF-I mRNA content was little affected by the test diet and starvation

Growth performance of sea bass fed increasing levels of pea-wheat protein in diets varying in fish meal quality

A 11-week trial was carried out to compare the growth performance of sea bass (D. labrax) fed six isonitrogenous isocaloric diets where protein from two fish meals of different nutritive value was replaced with graded levels (0, 50 or 75%) of a mixture made up by a pea protein concentrate and wheat gluten. Fish meal quality did not affect (P>0.05) weight gain or feed efficiency in fish fed graded levels of plant protein in the diet. Feed intake decreased (P<0.05) as the level of plant protein was increased in the diet but this did not led to impaired growth or feed conversion rate. Protein efficiency and retention were equally improved (P<0.05) only with diets where a poor quality fish meal was substituted by protein rich-plant ingredients. Calculations based on the mass balance of nutrients of sea bass proven the inclusion of a mixture of highly purified plant-protein derivatives in complete diets for the sea bass, to be beneficial in reducing pollution load

Modulation of Extra Virgin Olive Oil Digestibility through Oleogelation

Background. Extra virgin olive oil (EVOO) represents a key player in the Mediterranean diet for its health-promoting capacity. Although its use as a functional ingredient would be particularly interesting, the direct addition of EVOO to food is challenging due to its liquid state. EVOO conversion into a solid-like material through by oleogelation could enlarge its possible applications. Methods. EVOO was gelled by adding 10% (w/w) of saturated monoglycerides (MG), rice bran waxes (RW), sunflower waxes (SW) or a β-sitosterol/γ-oryzanol mixture (PS). Oleogels were characterised for their structure and subjected to static in vitro digestion. The fatty acid release and destructuring behavior were assessed. Results. The resulting oleogels differed for rheological properties and firmness due to the differences in gel network structure. PS oleogel was the firmest sample followed by SW, RW and MG ones. During in vitro digestion, the fatty acid release was significantly lower for all oleogels compared to unstructured oil. The different network provided by the four oleogelators not only influenced FA release, but also the intestinal micellar size. Conclusion. Acquired results could open new horizons for EVOO application through oleogelation to obtain novel EVOO-based fat replacers and better deliver the EVOO health functionalities

Microemulsions as delivery systems of lemon oil and \u3b2-carotene into beverages: stability test under different light conditions

BACKGROUND: Microemulsions have been proposed as delivery systems for different lipophilic substances in transparent water-based systems. The chemical stability of the delivered compounds is a key factor to broaden the application of microemulsions in the food sector. The stability of a model beverage containing a microemulsion delivering \u3b2-carotene and lemon oil was tested under increasing light intensity up to 6000 lx at 20 \ub0C. RESULTS: The transparent microemulsion resulted physically stable during storage indicating that no coalescence phenomenon occurred. On the contrary, both colour and flavour of the microemulsion degraded as a consequence of limonene and \u3b2-carotene oxidation. Kinetic data obtained at increasing light intensity were used to estimate the light dependence of beverage spoilage and the mathematical relationship obtained was used to predict spoilage rate under different light conditions. Finally, a shelf life predictive model was proposed. CONCLUSIONS: Transparent microemulsions can be successfully used to deliver flavoured oil and colourants into beverages. However, the photostability of the delivered compounds should be carefully studied to estimate product shelf life. To this aim, the availability of models predicting shelf life as a function of enlightening conditions could largely contribute to speed up the process

WATER\u2013BUDGET AS A TOOL TO EVALUATE THE SUSTAINABLE USE OF GROUNDWATER RESOURCES (ISONZO PLAIN, NE ITALY)

Water budget, hydrogeology, Soča/Isonzo River, climate chang

Welfare and quality of farmed trout fed high plant protein diets. 1 Growth performance and quality traits

AbstractThis study was performed to evaluate the effects of high levels of inclusion of plant protein sources to replace fish meal in rainbow trout (O. mykiss) diets on growth performance and quality characteristics. Two isoproteic (44.8%) and isolipidic (19.6%) extruded diets were fed to eight groups of trout (IBW 106.6g) for 103 days. Diet FM, containing only fish meal as protein source, was used as control treatment and compared to diet PV80, where a plant protein mix (pea protein concentrate and wheat gluten) was included to replace 80% of fish meal protein. Growth performance (FBW: 318.5g; SGR: 1.06%) and feed to gain ratio (0.79) of the fish were not affected by dietary treatment (p>0.05). Dry matter and protein ADCs, measured in vivo after stripping, resulted higher in fish fed the high vegetable protein diet relative to the fish meal one (p<0.05). Trout fed diet PV80 were characterised by higher agility index (2.02 vs 1.72, p<0.05), carcass yield (91.95 vs 91.18%, p<0.05), lower hepatosomatic inde..

Potential application of pomegranate seed oil oleogels based on monoglycerides, beeswax and propolis wax as partial substitutes of palm oil in functional chocolate spread

In this research, the effectiveness of pomegranate seed oil oleogel as a partial replacement of fat phase in chocolate spread was studied. Monoglyceride (MG), beeswax (BW) and propolis wax (PW) have been used as structuring agents at 5 g/100 g concentration to gel pomegranate seed oil. The oleogels were then combined with palm oil at 1:1 ratio. Different techniques, including polarized light microscopy, synchrotron XRD, mechanical analyses, and oil binding capacity were used to study the physical and mechanical properties of the palm oil-oleogel systems and chocolate spreads. Results highlighted that MG, BW and PW chemical nature led to the formation of different crystalline network in palm oil-oleogel systems. Chocolate spreads containing palm oil-oleogels showed an increase in the mechanical parameters in the order of PW < BW < MG. This trend might be attributed to the chemical composition of oleogelators and physical bonds formed in the samples. During storage, crystal transformation in MG and structural reorganization in waxes (PW and BW) samples showed a gradual decrease and increase in hardness, respectively. These findings could provide useful information in the application of pomegranate seed oil oleogel for novel confectionery products engineering