Aktuelle Themen

Aktuelle Themen

Aktuelle Themen

José Pestana, Cristina Alfaia, Susana Alves, Marta Madeira, José Santos-Silva, Olga Moreira, Rui Bessa, Fidel Toldrá, José A. M. Prates
Total lipid content and fatty acid ­composition in edible offal from pigs
Gesamtlipidgehalt und Fettsäurezusammensetzung in essbaren Schlachtnebenprodukten von Schweinen

The objective of this study was to investigate the lipid content and fatty acid profile in six edible organs, namely heart, brain, pancreas, kidney, liver, and tongue from commercial crossbred pigs. Results indicate that total lipid and fatty acid composition were significantly affected by organ type. Large differences in lipid contents were found, ranging from 1.4 to 6.8 g/100 g of tissue. Brain had the highest lipid content followed by tongue, pancreas, liver, kidney, and heart. The fatty acid profile revealed low relative proportions of saturated fatty acids (SFA) in heart. In contrast, higher amounts of un­saturated fatty acids were obtained for heart (PUFA), and tongue (MUFA). Heart and kidney had the most favourable PUFA/SFA ratio. However, the ratio of n-6 and n-3 PUFA in by-products from pigs was above to the nutritional recommendation for human diet, except in brain. Moreover, variations in fatty acid profile clearly highlight the differences between the organs as showed by principal component analysis. Our findings indicate that some edible offal from pig were relatively rich in SFA and, therefore, should be consumed moderately if integrated into a varied well-balanced diet.

Samer Mudalal, Bassam Ali Abu-Shanab, Jihad Abdallah
Evaluation of Physico-chemical Properties and Selected Antibiotic Residues in UHT Milk Marketed in Palestine
Bewertung physikalisch-chemischer Eigenschaften und ausgewählte ­Antibiotikarückstände in UHT-Milch, die in Palästina vermarktet wird

Ultra-high temperature (UHT) milk products have the main market share in the Palestinian local dairy market. The aim of this study was to evaluate the sensory, physico-­chemical and microbiological quality of UHT milk. In total 30 milk packs from Low and whole-fat UHT were selected from three different (two locals and one foreign labeled as A, B, and C) companies to evaluate physico-chemical properties (viscosity, density, freezing point, acidity, fat, protein, sensory traits, mineral composition, etc) and some microbiological parameters. Moreover, milk samples were tested for presence of residues of three commonly used antimicrobial drugs (Penicillin G, Sulfamethazine, and Tetracycline). Our study showed that there were significant differences (P < 0.05) in fat content among companies (3.56, 2.98, and 3.03% for A, B, and C companies, respectively). The non-compliance% in fat content with respect to labeled fat content ranged from –0.7% (for company B) to +18.7% (company A) in whole milk product, and +2.0% (company C) to +115% (company B) in low fat milk. Whole milk product from company B showed 4.75% of water addition which was significantly larger in comparison with other sources. Moreover, UHT milk products from company B exhibited 10% of positive results of antibiotic residues (+Sulfamethazine) which was significantly higher than other sources of milk products, and at the same time was higher than the Maximum Residue Level (MRL = 100 µg/L). In conclusion, this study showed that some of UHT milk products that are available in the Palestinian market do not fully meet the nutritional labeling (particularly in regard to fat content) and there were some violations in safety criteria.

Muhammad Tayyab Rashid, Haile Ma, Bushra Safdar, Mushtaque Ahmed Jatoi, Asif Wali, Frederick Sarpong, Cunshan Zhou
Synergy of ultrasound and osmotic ­dehydration in improving drying kinetics and quality of dried sweet potato ­(Ipomea batatas L.)
Synergieeffekte von Ultraschall und osmotischer Dehydrierung zur ­Verbesserung der Trocknungskinetik und der Qualität von getrockneten ­Süßkartoffeln (Ipomea batatas L.)

The effect of ultrasonic pretreatment and combined ultrasonic-osmotic dehydration using different pretreatment times (10, 20, 30, and 45 min) at 60°C was investigated. The aim of the present work was to shorten the total drying time and to improve the quality of sweet potato slices. The results showed that the moisture effective diffusivity increased when ultrasound was used as pretreatment to reduce the drying time, while the osmotic solution had no effect on moisture diffusivity. Among different ultrasound pretreatment timings, 30 min ultrasonically osmotic dehydrated treatment (US/GC-10%-3) proved the best in drying time reduction, which showed that ultrasound has a positive impact on osmotic dehydration. The drying kinetics of sweet potato slices were improved by sonication, which involves an improvement of mass transfer coefficient and drying rate. The logarithmic model showed the best fit to the experimental data for all treatments. For ultrasound treated samples, the parameters including enzyme inactivation, color, microstructure, mass transfer parameter had significant changes in comparison with distilled water treated and osmotically treated samples of sweet potatoes.

Cigdem Mecitoglu Gucbilmez, Omer Oksuz, Muhammet Arici
Fortification of edible zein films with thyme, laurel and orange essential oils and determination of their antifungal and radical scavenging properties
Anreicherung von essbaren Zeinfilmen mit ätherischen Ölen aus Thymian, Lorbeer und Orange und Bestimmung ihrer antifungalen und radikalfangenden Eigenschaften

The purposes of this research were: (a) to produce zein films by adding certain essential oils (EOs), (b) to identify their antifungal activity on some yeasts and molds, and (c) to develop an edible zein film that can inhibit the growth of Aspergillus fumigatus which was identified in a previous study as the most heat resistant mold isolated from margarines. Zein films fortified with thyme (Thymus vulgaris), laurel (Laurus nobilis) and orange (Citrus sinensis) EO were tested for their antifungal activities against 3 molds and 5 yeasts by measuring inhibition zone diameters. Considering the single effect, thyme EO was determined as the most effective one. Furthermore, the antifungal activities of thyme EO combined with the other EOs were also studied. From the obtained data, films containing thyme EO in combination with laurel EO were found as the most effective against Aspergillus fumigatus. Then, minimally inhibitory concentration against Aspergillus fumigatus was determined for the zein film obtained from film solutions including only thyme EO as 1.7 % (v/w), combinations of thyme-laurel EO as 1.6 % (v/w). Also, thyme oil was found as EO having the highest radical scavenging activity and total phenolic compounds among the three EOs.