Nives Marušić Radovčić

This study evaluated how corn grain hardness, vitamin A supplementation level, and trace mineral form influence production performance and egg properties in laying hens. In a 2 × 3 × 2 factorial design, 252 Lohmann Brown hens received diets containing soft- or hard-type corn hybrids; 5000, 10,000, or 20,000 IU/kg of vitamin A; and inorganic or organic trace minerals for 63 days. Hard-type corn increased daily egg mass, improved feed conversion ratio, and produced eggs with higher MUFAs and SFAs but lower PUFAs and n-3, resulting in a less favorable n6/n3 ratio, while also increasing susceptibility to Fe-induced lipid oxidation despite lower PUFAs. Increasing dietary vitamin A to 10,000–20,000 IU/kg increased egg weight and shell strength, linearly increased yolk retinol, and decreased tocols, with 20,000 IU/kg markedly increasing Fe-induced MDA formation without major changes in PUFAs. Trace mineral form had minor effects on performance and fatty acid profile. Overall, modest changes in laying hen diet, such as corn hybrid, vitamin A supplementation level, and trace mineral form, significantly modulated egg nutritional composition and oxidative stability. A high dietary vitamin A level may compromise the oxidative resilience of enriched eggs, while interactions of trace mineral form with corn hybrid and vitamin A suggest its potential modulatory role in lipid oxidation pathways.

Ziel dieser Studie war es, die antioxidative Aktivität von geräucherten Rohschinkenproben zu bestimmen, darunter sowohl ungeschützte Rohschinken als auch zertifizierte dalmatinische Schinken mit geschützter geografischer Angabe (g.g.A.). Geräucherter Rohschinken ist ein traditionelles Produkt, dessen Nährwert und sensorischer Wert auf einem komplexen Trocknungs- und Reifungsprozess beruht und das zunehmend als Quelle bioaktiver Verbindungen mit potenziell positiven physiologischen Wirkungen anerkannt wird. Die Bewertung der antioxidativen Aktivität von geräuchertem Rohschinken kann nichtnur für das Verständnis seiner funktionellen Eigenschaften nützlich sein, sondern auch als zusätzlicher Parameter für die Aufwertung des Produkts. Die antioxidativen Eigenschaften von geräuchertem Rohschinken werden in erster Linie auf das Vorhandensein bioaktiver Peptide zurückgeführt, die bei der Proteolyse von Muskelproteinen entstehen. Diese Verbindungen können dazu beitragen, den oxidativen Stress zu verringern und das Risiko der Entstehung degenerativer Krankheiten zu senken. Insgesamt wurden 14 Schinkenproben analysiert, darunter 9 ungeschützte und 5 IGP-zertifizierte Produkte. Die antioxidative Aktivität wurde im Muskel Biceps femoris mit zwei komplementären Analysemethoden - DPPH und FRAP - gemessen, die jeweils auf unterschiedlichen Mechanismen der Interaktion mit freien Radikalen beruhen. Die DPPH-Methode zeigte, dass die Radikalfängerkapazität zwischen 10,54 ± 1,17 % und 29,20 ± 1,04 % lag. Bei Anwendung der FRAP-Methode, die die Reduktionskraft der Probe misst, lagen die Absorptionswerte zwischen 0,28 ± 0,02 und 0,88 ± 0,04 bei einer Wellenlänge von 700 nm. Die Ergebnisse deuten auf ein beachtliches antioxidatives Potenzial der Schinkenextrakte hin. Obwohl ihre Aktivität im Vergleich zu synthetischen Antioxidantien geringer ist, machen der natürliche Ursprung dieser Verbindungen und ihre mögliche biologische Wirksamkeit ohne schädliche Nebenwirkungen den geräucherten Rohschinken zu einer wertvollen Quelle für natürliche Antioxidantien. Diese Studie unterstreicht die Notwendigkeit weiterer Untersuchungen, um das funktionelle Potenzial dieser traditionellen Produkte vollständig zu bewerten.

The inclusion of linseed in cattle diets can improve the fatty acid (FA) profile of meat, but the effects of supplementation at different ages have been insufficiently studied. Hence, this study examined the effects of linseed supplementation and slaughter age on beef cattle carcass and meat quality, FA profile, and lipid oxidation. Eighty Simmental bulls (initial age 221 ± 9 days) were evenly allocated the experimental treatments, consisting of a control diet and a linseed-enriched diet (around 1% whole linseed) fed to the bulls until slaughter at 13 or 17 months of age, in a 2 × 2 factorial design. After slaughter, carcass traits, meat quality, FA profile, and oxidative stability (TBARS test) of the longissimus thoracis muscle were determined. Linseed feeding increased the dressing percentage (p < 0.01) at both slaughter ages but had limited effects on overall carcass and meat quality. The intramuscular fat of linseed-fed bulls contained less saturated FA (p < 0.01) and more beneficial n-3 PUFAs, such as eicosapentaenoic (p < 0.05) and α-linolenic acid (p < 0.001), especially in younger bulls. Although the atherogenic index and n-6/n-3 ratio improved, they remained above the recommended values. Lipid oxidation was higher in linseed-fed (p < 0.05) and younger bulls (p < 0.001). These results suggest that linseed supplementation can improve the beef’s FA composition, but higher levels, especially in older animals, and antioxidant strategies may be required to optimise meat stability and nutritional value.

This study compares Dalmatinski pršut, an EU Protected Geographical Indication (PGI)-labelled smoked dry-cured ham from the Dalmatia region in Croatia, with non-PGI hams from the same area, focusing on the impact of PGI certification on the product quality. The investigation is prompted by the increasing presence of dry-cured hams lacking the PGI label on the market, aspiring to compete with esteemed high-value PGI products. Samples of 28 smoked dry-cured hams (12 PGI and 16 non-PGI) were analysed for chemical properties, fatty acid composition, volatile compounds, PAH content and sensory characteristics. The results showed that PGI and non-PGI hams differ in their chemical and physical properties, with non-PGI hams having a lower water content and a higher salt content, which was also confirmed by the saltier taste in the sensory evaluation. PGI hams had a lower b* colour value, and, while the differences in texture were minimal, non-PGI hams had slightly more monounsaturated fatty acids. The aroma analysis revealed that PGI hams contained more aldehydes and alcohols, while non-PGI hams had a higher content of phenolic compounds and aromatic hydrocarbons, probably due to differences in smoking practices. PAH levels, however, were within the EU limits, indicating controlled smoking of both type of hams. Overall, these results show that the quality of smoked dry-cured ham can be distinguished by the PGI designation. The study illustrates how the traditional production methods prescribed by the PGI production protocols shape the sensory and chemical profiles of Dalmatinski pršut, with the PGI certification playing a crucial role in maintaining product quality and certifying its typicality, to distinguish it from non-PGI products.

Excessive sodium consumption is a worldwide problem, prompting the industry to develop sodium-reduced products and substitute salts. High sodium consumption is a significant risk factor for high blood pressure, cardiovascular disease and kidney disease. Excessive sodium intake also impairs the immune system in the gastrointestinal tract. Potassium chloride (KCl) is the most commonly used mineral salt due to its similarity to sodium chloride (NaCl), and its consumption has been shown to lower blood pressure when consumed in adequate amounts. The aim of this study was to partially replace NaCl with KCl at levels of 25%, 50% and 75% in the brine used to make white brined cheese. Parameters such as acidity, total dissolved solids, salinity, conductivity, colour, texture and sensory properties were evaluated during a 28-day refrigerated storage period. KCl can replace NaCl by 50%, and no significant differences in physicochemical and sensory parameters were observed during cheese storage compared to the control sample. In addition, the study investigates the use of Artificial Neural Network (ANN) models to predict certain brine and cheese properties. The study successfully developed four different ANN models to accurately predict various properties such as brine pH, cheese colour and hardness over a 28-day storage period.

This study investigated the potential of olive leaf extract (OLE), as a functional ingredient, to improve cheese properties, because it is rich in phenols. Milk and dairy products are poor in phenolic compounds. The main objective was to determine the most effective coagulation method and timing of OLE supplementation to maximize retention in the cheese matrix. Experimental cheeses were produced using the rennet and acid coagulation methods, with OLE added either directly to the cheese milk or to the curd phase. Three OLE effective concentrations corresponding to 25%, 50%, and 75% inhibition of DPPH reagent (EFC25, EFC50, and EFC75, respectively) were added, i.e., 11.5 mg GAE L⁻¹, 16.6 mg GAE L⁻¹, and 26.3 mg GAE L⁻¹, respectively. The results showed that OLE significantly increased the concentration of total phenols, total flavonoids, and antioxidant activity in all cheese samples and in the residual whey, especially at higher effective concentrations (EFC 50 and EFC 75). Rennet-coagulated cheese to which OLE was added prior to coagulation (EM 25, EM 50, EM 75) exhibited higher hardness, gumminess, and chewiness but lower elasticity, suggesting alterations in the paracasein matrix. OLE did not adversely affect acidity, water activity, or cheese yield. However, higher EFC resulted in significant colour changes (∆E* > 3.0). In conclusion, the enrichment of cheesemaking milk with OLE and the application of the rennet coagulation method are the most suitable to optimise the production of OLE-enriched cheese. This research shows the potential to improve the nutritional value of cheese while maintaining its desired characteristics.

The Turopolje pig (TP) is a local Croatian pig breed that almost became extinct in the second half of the 20th century. Today, the TP is still endangered, and a new conservation strategy based on products with higher added value is needed to preserve the breed. There is little information on the quality of TP meat products such as smoked and dry-cured ham, including the impact of natural feeds or processing innovations such as smoke reduction. This study, therefore, investigated the effects of the animal’s diet (either conventionally fed or acorn-supplemented) and the processing method (standard or lightly smoked) on the quality traits of dry-cured TP ham. Twenty hams, evenly distributed among the treatments, were processed for 15 months and then analysed for physicochemical and textural traits, volatiles and sensory profile. The hams from acorn-supplemented pigs lost less weight during processing (p ≤ 0.05). Otherwise, the diet had no significant effect on most examined ham traits. The exceptions were protein content and the texture parameter hardness, which decreased (p ≤ 0.05), and the degree of proteolysis and colour parameters, which increased (p ≤ 0.05) as a result of acorn supplementation. However, these effects were generally small and varied between the inner (m. biceps femoris) and outer (m. semimembranosus) muscles. Furthermore, acorn supplementation was associated with less typical ham odour and lower sensory scores for sweetness and colour uniformity (p ≤ 0.05). The smoke reduction had no effect on the physicochemical and colour properties but resulted in a significant reduction (p ≤ 0.05) in the volatile phenolic compounds and an improved texture to the hams. This was reflected both in reduced (p ≤ 0.05) hardness, identified in the instrumental analysis, and in an increased (p ≤ 0.05) softness, solubility and moistness, identified in the sensory evaluation. To summarize, the quality of the TP ham under the conditions studied was only slightly affected by acorn supplementation, whereas reduced smoking had a more significant effect, which was mainly reflected in an improved texture.

Cilj istraživanja bio je odrediti koncentracije policikličkih aromatskih ugljikovodika (PAH) u dimljenom pršutu nakon 12 i 18 mjeseci zrenja. Istraživanje je provedeno na uzorcima dvaju mišića pršuta: biceps femoris (BF) i semimembranosus (SM). Prisutnost PAH spojeva u istraživanim mišićima određena je metodom visoko učinkovite tekućinske kromatografije s fluorescencijskom detekcijom (HPLC-FLD). Rezultati istraživanja pokazali su da se PAH spojevi više akumuliraju u mišiću SM zbog njegovog vanjskog položaja i veće izloženosti vanjskim faktorima, posebno dimljenju. Također, istraži vanje je pokazalo da su se koncentracije većine PAH spojeva značajno smanjile nakon 18 mjeseci zrenja u oba mišića. Koncentracije benz(a)pirena (BaP) i PAH4 (BaP, BaA, BbF, Chr), koji mogu biti potencijalno štetni za ljudsko zdravlje, nisu premašile vrijednosti propisane od strane Europske komisije za mesne proizvode, što čini Dalmatinski pršut sigurnim za konzumaciju.

Background: White brined cheese is one of the most frequently consumed cheeses that is accepted among a large group of consumers, which is largely related to its unique sensory properties, which are characterized by specific technological processes including ripening in the brine. Thus, white brined cheese contains a high amount of NaCl, and frequent consumption might lead to excessive sodium intake, which nowadays, presents a global problem. Consequently, food industries have developed reduced sodium products by substitutional salts. Furthermore, various studies have indicated that increased sodium intake via the diet can be associated with cardiovascular diseases, a risk of digestive system cancer, obesity, and other conditions. Calcium salts (citrate and lactate) are safe for human health and can be added to various foods according to the quantum satis rule. The present study aimed to partially replace NaCl with Ca-citrate and Ca-lactate in proportions of 25% and 50%. Additionally, the study presents the possibility of applying Artificial Neural Network (ANN) models for the prediction of some brine and cheese properties. Methods: White brined cheese with substitutional salts in brine (25% and 50% Ca-citrate and 25% and 50% Ca-lactate) were produced and compared to the control cheese ripened in conventionally applied NaCl brine. The acidity, total dissolved solids, salt amount, conductivity, color, and textural and sensory properties were determined over the 28 days of cold storage. Results: The substitution of NaCl with Ca-citrate and Ca-lactate is promising for sodium reduction in white brined cheese, whereby the physical and chemical properties remain acceptable. The best sensory score gain occurred with a substitution of 25% NaCl with Ca-citrate. Furthermore, ANN models can be employed to predict brine and cheese properties during storage.

Peptide und freie Aminosäuren entstehen in trocken gepökeltem Schinken aufgrund intensiver Proteolyse durch die Wirkung von Muskelpeptidasen. Die Proteolyse führt zur Bildung großer Mengen freier Aminosäuren und vieler Peptide mit unterschiedlichen Sequenzen und Längen, von denen einige relevante Bioaktivitäten aufweisen, wie z. B. die Hemmung des Angiotensin-Converting-Enzyms, antioxidative Aktivität, blutdrucksenkende, blutzuckersenkende oder entzündungshemmende Wirkung. In diesem Beitrag werden neuere Erkenntnisse vorgestellt, die zeigen, dass Rohschinken eine gute Quelle für natürliche bioaktive Peptide ist, die einen potenziellen Nutzen für die menschliche Gesundheit haben. Die bioaktiven Peptide selbst werden beschrieben, ebenso wie ihre Rolle und ihre positiven Auswirkungen auf die menschliche Gesundheit. Außerdem werden die bioaktiven Peptide, die in Rohschinken enthalten sind, ihre Funktionen und ihre Bedeutung beschrieben. Bioaktive Peptide können die Oxidation von Lipiden und Proteinen in Rohschinken verringern oder verhindern und so zu einer besseren Qualität des Produkts beitragen.