Aktivnost zgrušavanja mlijeka i primarna proteoliza liofiliziranog ekstrakta cvijeta artičoke (Cynara scolymus L.)

Research background. A few studies have investigated Cynara scolymus enzymes as a substitute for calf rennet in cheese making. They used aqueous extracts prepared by maceration of plant material and stored by freezing. However, it was indicated that lyophilisation is a better alternative to preserve the coagulant properties of plant extracts over a longer period of time, as it is a more controllable, stable and hygienic alternative with a better shelf life that is easier to transport, store and standardise. Experimental approach. We obtained a lyophilised extract of mature artichoke flowers, named CS, which was characterised for its milk-clotting properties at different pH and temperatures. In addition, the potential yield, whey composition and the primary hydrolysis profile of caseins by urea-polyacrylamide gel electrophoresis (PAGE) of mini curds prepared with different doses of coagulant were determined. Results and conclusions. The lyophilised extract was able to hydrolyse casein and showed stable proteolytic activity at pH=6.4 and 37 °C for 50 min, which decreased when the process temperature was increased to 41 and 45 °C and was lost at 70 °C. On the other hand, milk-clotting activity increased significantly (p<0.001) when the temperature increased from 37 to 45 °C and the pH of the milk decreased from 6.8 to 5.8. Potential yield ​​between 10 and 17 % was obtained for the mini curds prepared with the lyophilised artichoke extract, and the casein degradation pattern obtained by urea-PAGE was similar to that of the commercial coagulant. Novelty and scientific contribution. On a laboratory scale, our work has shown that the lyophilised artichoke extract has sufficient proteolytic and coagulant activity to be used as a milk coagulant, i.e. plant rennet, in cheese making as an alternative to animal rennet. As this extract is lyophilised, it has the advantage of being a better alternative in terms of preservation and shelf-life. It offers an innovative way to diversify cheese products and appeal to consumers with different dietary preferences and needs.Pozadina istraživanja. U nekoliko je istraživanja ispitana primjena enzima dobivenih iz artičoke (Cynara scolymus) kao zamjena za teleće sirilo u proizvodnji sira. U njima su korišteni vodeni ekstrakti dobiveni maceracijom biljnog materijala te skladišteni zamrzavanjem. Međutim, pokazalo se da se liofilizacijom bolje očuvaju koagulacijska svojstva biljnih ekstrakata tijekom duljeg skladištenja, jer ih je jednostavnije kontrolirati, održati stabilnima i higijenski ispravnima, a mogu se i dulje vrijeme skladištiti te lakše distribuirati i standardizirati. Eksperimentalni pristup. U ovom smo radu pripravili liofilizirani ekstrakt cvijeta zrele artičoke, te opisali njegova svojstva zgrušavanja mlijeka pri različitim pH-vrijednostima i temperaturama. Osim toga, određeni su mogući prinos, sastav sirutke i uzorak razgradnje kazeina u grušu pripremljenom u malim porcijama s različitim količinama sredstva za koagulaciju, ispitanom elektroforezom na poliakrilamidnom gelu s dodatkom uree. Rezultati i zaključci. Liofilizirani ekstrakt je razgradio kazein i imao stabilnu proteolitičku aktivnost pri pH-vrijednosti od 6,4 i temperaturi od 37 °C tijekom 50 min, koja se smanjila pri porastu temperature na 41 i 45 °C, a potpuno nestala pri 70 °C. Nasuprot tome, aktivnost zgrušavanja mlijeka se bitno povećala (p<0,001) pri porastu temperature s 37 na 45 °C i padu pH-vrijednosti mlijeka sa 6,8 na 5,8. Mogući prinos gruša pripremljenog u malim porcijama pomoću liofiliziranog ekstrakta artičoke bio je od 10 do 17 %, a uzorak razgradnje kazeina određen elektroforezom na poliakrilamidnom gelu s dodatkom uree bio je sličan uzorku dobivenom primjenom komercijalnog koagulanta. Novina i znanstveni doprinos. Naše istraživanje provedeno u laboratorijskim uvjetima pokazalo je da liofilizirani ekstrakt artičoke ima dovoljno veliku proteolitičku aktivnost i sposobnost koagulacije, pa se može upotrijebiti kao sredstvo za zgrušavanje mlijeka, odnosno u proizvodnji sira kao koagulant biljnog podrijetla, umjesto sirila životinjskog podrijetla. Prednost liofiliziranog ekstrakta je u tome što bolje zadržava koagulacijska svojstva i može se dulje vrijeme skladištiti. Osim toga, pruža inovativnu mogućnost proizvodnje različitih vrsta sireva, što može biti zanimljivo potrošačima koji imaju različite prehrambene potrebe i navike

molecular and morphological identification of an uncommon centrolophid fish

AbstractThe use of both morphological and molecular methods has allowed a fast and reliable species assignment of a fish that local fishermen with over thirty years of experience had never seen before. The identified species, Schedophilus medusophagus, is rare along Italian coasts, and this is the first documented record in the Central Tyrrhenian Sea for over 35 years. Its abundance should be evaluated on a continuous basis, as it might reflect biological consequences of environmental and climatic change. The mitochondrial sequences obtained in this study constitute a useful molecular tag for future research and may contribute to the phylogenetic debate on the status of the genus Schedophilus, of which S. medusophagus is the type species. Based on the existing literature, these preliminary molecular data support the hypothesis that the genus is not monophyletic

BRCA mutation carriers' perceptions on postmenopausal hormone therapy: An Italian study

Objective To evaluate the actual perceptions of postmenopausal hormone therapy (HT) in BRCA mutation carriers (BRCAmc) in comparison with women from the general population.Methods Questionnaire-based study of 83 BRCAmc and a control group of 89 women without a genetic mutation. Perceptions were evaluated by specific questions and Likert scales (-5-+5).Results Present and past users of HT were more frequent in the control group (p = 0.01), with a longer time of use (p = 0.03). The preferred route of administration of HT was 'oral' (54.6%). The most frequently reported adverse effect of HT was venous thrombosis (0.8), while a protective effect on bone health was reported. No noticeable beneficial effects of HT have been recognised for hot flushes (0.2) and vaginal dryness (0.1). The most frequently perceived beneficial and adverse effects of HT were not significantly different between BRCA mutation carriers and controls. The greatest oncological fear was breast cancer (1.0). The protective role of HT on colorectal cancer was not known (0.1). These oncological impacts were mostly overestimated in BRCAmc, however this was not significant. Few BRCAmc would think of taking HT after risk-reducing surgeries.Conclusions Knowledge of the effects of HT on BRCAmc is relatively poor and they are likely to overstate its negative effects and underestimate its health benefits; however, this is not significant in comparison to the general population. More and better information should be given to BRCAmc to allow them to make informed decisions about the use of HT, especially before undergoing risk-reducing surgeries

Silicon sensors with resistive read-out: Machine Learning techniques for ultimate spatial resolution

Resistive AC-coupled Silicon Detectors (RSDs) are based on the Low Gain Avalanche Diode (LGAD) technology, characterized by a continuous gain layer, and by the innovative introduction of resistive read-out. Thanks to a novel electrode design aimed at maximizing signal sharing, RSD2, the second RSD production by Fondazione Bruno Kessler (FBK), achieves a position resolution on the whole pixel surface of about 8 $\mu m$ for 200-$\mu m$ pitch. RSD2 arrays have been tested using a Transient Current Technique setup equipped with a 16-channel digitizer, and results on spatial resolution have been obtained with machine learning algorithms.Comment: 2 pages, 2 figur