Effects of starter culture and storage on volatile profiles and sensory characteristics of yogurt or cream butter

U ovom istraživanju ispitivan je utjecaj starter kulture na hlapive sastojke i senzorska svojstva maslaca proizvedenog od vrhnja, odnosno od jogurta tijekom 60 dana hladnog skladištenja. Kao starter kulture korišteni su sojevi Lactococcus lactis subsp. lactis biovar. diacetylactis, Leuconostoc mesenteroides subsp. cremoris te njihova kombinacija. Utvrđeno je formiranje ukupno 10 estera, 6 aldehida, 11 ketona, 16 alkohola, 6 kiselina, 2 sulfida, 3 terpena i 3 atipična sastojka. U pravilu je maslac od vrhnja sadržavao više hlapivih sastojaka nego maslac od jogurta. Prisutnost S-metil tioacetata utvrđena je samo u maslacu od jogurta, dok su u maslacu od vrhnja bili prirodno prisutni heksanal, etanol, 2-nonanon, 2-pentanon, 2-heptanon, acetat, maslačna i kapronska kiselina. Iako se maslac od jogurta inače proizvodi bez startera, dobiveni rezultati su pokazali kako bi korištenje starter kultura u proizvodnji ovog tipa maslaca pozitivno utjecalo na stvaranje hlapivih sastojaka te na njegova senzorska svojstva. Maslac proizveden korištenjem kombinirane starter kulture dobio je najviše ocjene za prihvatljivost.In this study volatile compounds and sensory properties of butter produced from cream or yogurt using Lactococcus lactis subsp. lactis biovar. diacetylactis or Leuconostoc mesenteroides subsp. cremoris as well as a mixture of these two bacteria were investigated over 60 days. A total of 10 esters, 6 aldehydes, 11 ketones, 16 alcohols, 6 acids, 2 sulphides, 3 terpenes, and 3 miscellaneous compounds were detected. There were more volatile compounds in cream butter than in yogurt butter. While S-methyl thioacetate was only found in yogurt butter samples, hexanal, ethanol, 2-nonanone, 2-pentanone, 2-heptanone, acetic, butanoic (butyric) and hexanoic acid were the most abundant volatiles in both cream and yogurt butter. The results showed that the use of starter in the manufacturing of yogurt butter, which is traditionally produced without starters, affected the volatile compounds and sensory properties. The highest general acceptability scores were given to the butter samples containing mixed cultures at the end of storage

Influence of purple basil extract (Ocimum basilicum L.) on chemical composition, rheology and antioxidant activity of set-type yoghurt

U ovom istraživanju proizvedene su 4 vrste jogurta obogaćenog ljubičastim bosiljkom koji je dodavan u obliku vodenog ekstrakta ili kao prah u količinama 1,0 % i 0,4 % (w/w). Tako dobiveni uzorci jogurta skladišteni su 21 dan unutar kojih su im određivana fizikalno-kemijska i reološka svojstva, antioksidacijski kapacitet, boja i koncentracija ukupnih fenola. Nisu utvrđene promjene u titracijskoj kiselosti, pH vrijednosti i čvrstoći gruša, međutim, određene promjene zabilježene su prilikom skladištenja. Koncentracija ukupnih fenola i antioksidacijski kapacitet [diamonijeva sol 2,2’-azino-bis(3-etilbenzotazolin-6-sulfonske kiseline (ABTS+*) i 2,2-difenil-1-pikrilhidrazil(DPPH*)] bili su znatno veći u uzorcima jogurta kojima je dodavan prah u usporedbi s uzorcima kojima je dodavan vodeni ekstrakt, dok je najniža koncentracija ukupnih fenola i najniža ABTS vrijednost utvrđena u kontrolnom uzorku prilikom skladištenja. Vrijednosti određivanih reoloških parametara za promjene tijekom skladištenja i gubitak konzistencije bili su veći kod uzoraka s dodatkom vodenog ekstrakta. Zaključno, nije utvrđen značajan utjecaj dodatka praha ili vodenog ekstrakta bosiljka na kemijski sastav i svojstva jogurta, dok je pozitivno utjecao na antioksidacijski kapacitet i izmijenio reološka svojstva jogurta.Four different types of yoghurt were manufactured using purple basil which was added to milk as water extract or powder forms at levels of 1.0 % and 0.4 % (w/w). Physicochemical and rheological properties, antioxidant capacity, color and total phenolic contents of yoghurt samples were measured during 21 days of storage. None of changes were observed for titratable acidity, pH and hardness parameters of yoghurt samples; however, some changes were observed during storage. The contents for total phenolic compounds and antioxidant activity [2,2\u27-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid diammonium salt (ABTS+*) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH*) values] were dramatically higher in powder-added yoghurt samples than those of its water extract counterparts, while the lowest total phenolics and ABTS+* were observed in control sample during storage. The values for storage and loss modulus were higher in water extract-added samples than powder-added counterparts. In conclusion, no significant effect of the addition of powder or water extract of basil was observed on gross chemical characteristics of yoghurt, while use of basil powder positively contributed to antioxidant activity and changed the rheological behavior of yoghurt gel

Polyphasic identification of Penicillia and Aspergilli isolated from Italian grana cheese

"Available online 18 January 2018"Penicillium and Aspergillus genera, both including mycotoxin producing species, were reported as associated to cheese and cheese working environment, but never studied in an extensive way in Italian grana cheese (Grana Padano and Parmigiano Reggiano). The aim of this work was to address the identification of Aspergilli and Penicillia associated to grana cheese in order to lay down the basis for risk assessment and safe processing for a high quality production. One hundred and four strains belonging to Aspergillus and Penicillium genera were obtained from cheese crust and from ripening room air (with the latter largely dominant), and identified following a polyphasic approach, strongly required for the identification at the species level. Morphological observation was used along with molecular techniques, RAPD-PCR fingerprinting and calmodulin gene sequencing (CaM), the former aimed to limit as much as possible the latter sequencing effort. Seventy four percent of the strains were assigned to Penicillium subgenus Penicillium, section Fasciculata. Main mycotoxin producing species identified were A. flavus, P. crustosum and P. verrucosum, while the dominant species in both air and cheese crust was P. solitum, which has never been so far reported as mycotoxigenic. Results obtained in this study confirmed that mycotoxin contamination is a possible issue to face during grana cheese making.The present work was supported by the following institutions: Consorzio del Formaggio Parmigiano Reggiano, Consorzio per la tutela del Formaggio Grana Padano, Fondazione Romeo ed Enrica Invernizzi, the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/ 2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Simone Decontardi carried out this work within the PhD school “Agrisystem” of the Universita Cattolica del Sacro Cuore (Italy).info:eu-repo/semantics/publishedVersio

Polyphasic identification of Penicillium spp. isolated from Spanish semi-hard ripened cheeses

P. 409-444Fifteen samples of semi-hard ripened cheeses, both spoiled (10) and unspoiled (5), and obtained from cheese factories located in Northwest of Spain, were analysed by a dilution plating technique and direct sampling. A total of 32 isolates were identified at species level by a polyphasic approach (phenotypic characterization, partial extrolite analysis and molecular identification). Most isolates (65.6%) belonged to the species P. commune; other species found were P. solitum, P. chrysogenum, P. nordicum, P. expansum and P. cvjetkovicii. All of the P. commune isolates were able to produce cyclopiazonic acid, while the P. nordicum and the P. expansum isolates were producers of ochratoxin A and patulin respectively. Despite this, the role of P. commune as beneficial fungi in cheese ripening should be investigated. Molecular identification based on BenA sequence analysis was able to identify the majority of isolates. The three mycotoxins investigated can be considered key for identification. The polyphasic approach seems to be a very valuable tool for identification of isolates of this complex genusS

Changes in volatiles and essential oil composition of three organs (leaf, stem and flower) of purple basil (Ocimum basilicum L.) by GC–MS combined with multivariate statistical approach

The paper describes volatile compounds (in the organs for flower, leaf and stem) and essential oil contents in fresh or dried purple basil Ocimum basilicum L. grown in Turkey by using polar (TRB-WAX) or non-polar (DB-5MS) gas-chromatographic columns. dl-Limonene, 1,8-cineole, linalool, β-elemene, (Z)-methyl cinnamate and (E)-methyl cinnamate were major compounds of dried or fresh basil samples in polar column, while 1,8-cineole, linalyl acetate, l-linalool, α-terpinolene and (Z)-methyl cinnamate were major compounds of dried or fresh basil samples in non-polar column. 2-Pentanone, 1-pentanol, acetoin and methyl decadienoate were the volatiles detected only in dried basil samples, while 2,3-pentadione, p-xylene, delta-3-carene and o-xylene were found only in fresh basil samples. Furthermore, 1,8-cineole, linalool and methyl cinnamate were found to be the potent volatile compounds in purple basil essential oil with regardless of column type. Significant differences were also observed in the volatile components by using polar or non-polar columns. In conclusion, the multivariate statistical analysis and heat mapping showed that the plant organs contained different volatiles, and drying process significantly affected its concentrations in purple basil and its essential oil. Flower of the basil showed a distinct volatile composition with regardless of drying process and this was confirmed by both statistical approaches

Nutritional quality assessment in dairy products: A perspective

Many consumers are interested in the relationship between food quality and nutritional value when choosing to buy food. Dairy foods include a wide variety of foods such as liquid milk, fermented milks, cheese, cream, butter, and ice cream. Consuming milk and dairy products improves the overall nutritional quality of the diet. The chemical composition of dairy foods influences their nutritive value. Dairy foods provide substantial amounts of essential nutrients including fat, protein, lactose, calcium, potassium, phosphorus, magnesium, some vitamins (e.g., A, B1, B2, B12, and D), bioactive peptides, and lipids. Nutritional quality assessment is the key for protecting the high nutritional value of milk from farm to marketplace. This chapter deals with evaluating modifications and changes in nutritional components of milk and milk products in the course of processing, including recent processing techniques for minimal nutrient losses. © 2014, Springer Science+Business Media New York