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

The effects of production methods on the color characteristics, capsaicinoid content and antioxidant capacity of pepper spices (C. annuum L.)

The effects of production methods for red pepper flakes (RPF) and traditional (TRI) and industrial (INI) isot spices were evaluated with respect to the carotenoid and capsaicinoid contents, extractable color (ASTA color), surface color parameters, nonenzymatic browning (NEB), and the DPPH free radical-scavenging capacity of fresh red Capsicum (FRC). The measured characteristics were significantly affected by the processing methods used. RPF exhibited the highest antioxidant activity and best color quality in terms of carotenoid content, which was the highest; ASTA value; surface color intensity; and NEB, which was the lowest. In contrast, INI-processing methods resulted in poor color quality, causing the maximum increase in NEB. The concentration of capsaicinoid increased at the end of TRI processing, whereas it decreased in the two other methods. These results suggest that the traditional production method for isots prevents excessive destruction of their color attributes and contributes to the desirable characteristic browning.This study was supported by The Southeastern Anatolia Project Regional Development Administration, Republic of Turkey Ministry of Industry and Technology (Project: GAP-ISOT) and Harran University Scientific Research Institutions (HUBAK Project No: 14010). The authors thank the Experimental Station of the GAP Agricultural Research Institute for supplying the fresh peppers used in spice production

Isolation and characterization of a new potential source of bioactive peptides: White mulberry (Morus alba) fruits and its leaves

In this study, white mulberry (WM; Morus alba L.) and its leaf (WML) were hydrolyzed using enzymes at different preheating temperatures (50, 60, 70, 80, and 90 °C) with distilled water at a ratio of 1:10 (w/v). Pepsin, trypsin, chymotrypsin, and alcalase were employed for enzymatic hydrolysis, aiming to investigate the impact of heat treatment and enzymatic hydrolysis on bioactive properties; in particular, angiotensin-converting enzyme-inhibitory (ACE-i) and antioxidant activities. The highest hydrolysis efficiency was observed when using pepsin. The smaller peptides with <3 kDa had better ACE-i and antioxidant activities in both WM and WML samples. Regarding antioxidant activity, the highest level was identified at a preheating temperature of 90 °C in the WM sample, and at preheating temperatures of 50 °C and without heating in the WML samples. In conclusion, heat treatment and enzymatic hydrolysis were found to be a positive impact on ACE-i and antioxidant activities under various conditions. Moreover, the proteins derived from WM and WML were rich in the sources of potential ACE-i and antioxidant peptides

Changes in volatile compounds, sugars and organic acids of different spices of peppers (Capsicum annuum L.) during storage

Full Text ArticleChanges in sugars, organic acids and volatile compounds (VC) of red pepper flakes (RPF), traditional (TRI), and industrial (INI) isot peppers were evaluated during one year storage at the room condition. The changes in the flavor components were significantly affected by the production methods and storage time. Glucose content decreased gradually along storage and reduced by about 21.23, 47.22 and 56.65% for TRI, INI and RPF, respectively. However, fructose decreased significantly only in RPF (11.29%). Citric and succinic acids exhibited slight changes, but malic acid showed an increasing trend, especially in RPF (4-fold). Most of the VC in all samples decreased or disappeared after storage. The major quantitative losses in these compounds were found in TRI during the first 3 months as 81.76%. The storage was found to be caused deterioration flavor properties in red pepper spices and revealed the importance of appropriate storage conditions

Hydrogen incorporation into solvents can improve the extraction of phenolics, ‎flavonoids, anthocyanins, and antioxidants: A case-study using red beetroot

Different methods are used for extracting phytochemicals from plant produce. Some ‎methods require sophisticated and expensive instruments, while others need multiple steps ‎and specialist equipment, leading to an increase in energy, solvents, cost, and time. Here, the effect of incorporating hydrogen (H2) into solvents (that is water, ethanol, ‎methanol) on the extraction of flavonoids (TFC), phenolics (TPC), anthocyanins ‎‎(TAC), and antioxidants (DPPH and ABTS), as well as the extraction yield from red ‎beetroot, were evaluated. The biggest extraction yield was with the use of H2-rich ‎methanol (HRM) (24.32%). Incorporating H2 into water, ethanol, and methanol ‎led to a significant increase in TPC by 77.34, 39.02 and 89.07%, in the TFC by ‎‎43.30, 50.5 and 88.87%, in the TAC by 92.62, 199.5 and 257.41%. DPPH ‎scavenging activity increased by 6.49, 7.05 and 12.15%, and ABTS scavenging ‎activity by 3.93, 9.82 and 15.05%, respectively. The extraction of individual ‎phenolic compounds, using various solvents, were different for each compound ‎investigated, with HPLC analysis showing that the levels of some phenolics increased ‎when H2 was incorporated into the solvents. ‎This method, i.e., addition of H2 gas, is ‎suggested as a relatively cheap and practical method for increasing the extraction of ‎phytochemicals using an eco-friendly method