Juice and by-products from pomegranate to enrich pancake: characterisation and shelf-life evaluation

In this study, a fortified pancake with all parts of pomegranate as juice and by-products, added in the formulation, was designed. The influence of pomegranate addition on nutritional and sensory quality of pancake, as well as on its shelf-life, was assessed. As one would expect, the enrichment significantly improved the pancake polyphenolic content as compared to the control sample. Surprisingly, pomegranate addition did not affect its sensory quality. In fact, the enriched pancake was greatly appreciated from the sensory point of view. Results also suggested that the addition of pomegranate improved the glycemic index (GI). In fact, while a value of GI equal to 100 was obtained for the control sample, a GI of 71 was measured for the fortified sample. In terms of shelf-life, 30 days were obtained for the enriched pancake, whereas the control sample remained acceptable for about 26 days.     

Active packaging solution to prolong the shelf life of rocket salad

The best packaging conditions for rocket salad were assessed by subsequent experimental trials. In the first step, a preliminary screening of different packaging materials was performed and two micro‐perforated oriented polypropylene films with different micro‐hole diameters (90 and 110 μm) were selected as best packaging solutions. In the subsequent experimental step, modified headspace conditions were applied without any improvement on product quality. In the last step, the effects of an ethylene adsorbent were analysed. Rocket salad packaged in both films with the ethylene adsorbent recorded a shelf life of about 16 days, compared to the control samples that remained acceptable for 13 days. During storage, the microbial quality (mesophilic and psychrotrophic bacteria, pseudomonadaceae, lactic acid bacteria, yeasts, total coliforms and enterobacteriacae), the pH, the colour changes and the main sensory parameters were also monitored.     

Microbiological,physical and chemical characteristics of freshwater prawns (Macrobrachium rosenbergii) in modified‐atmosphere packaging

This study evaluated the influence of packaging atmosphere (air versus 50% N₂/50% CO₂) on microbiological (mesophiles, psychrotrophs), physical (gas measurement) and chemical (pH, total volatile basic nitrogen [TVB‐N], NH₃, H₂S and biogenic amines) parameters in freshwater prawns during storage at 0 ± 1 °C for 240 h. To select the most appropriate packaging, 21 batches of each treatment were analysed. Both the packaging permeability and the combination of gases affected the shelf life, but the modified‐atmosphere packaging (MAP) was more efficient than air packaging, increasing the shelf life by 40 h. The parameters of pH and TVB‐N showed no statistical difference between the two atmosphere conditions all along the storage period. The biogenic amine agmatine showed potential for use as a quality indicator due to the increased concentration during storage. In further studies, this amine can be applied as an indicator for public health issue.     

Chromatographic Methods for the Determination of Carbohydrates and Organic Acids in Foods of Animal Origin

Carbohydrates are ubiquitous and range from simple monosaccharides to large complex polysaccharides. Organic acids are compounds with acidic properties. Both occur naturally in many foods and in fermented products. Organic acids are usually derived from the hydrolysis of carbohydrates by microorganisms such as lactic acid bacteria. These bacteria convert carbohydrates into energy required for growth, since they are not equipped with the enzymes necessary for respiration and are unable to perform oxidative phosphorylation. Determination of carbohydrates and organic acids in foods of animal origin is important, since they contribute to flavor and texture. Their presence and proportions can affect the chemical and sensory characteristics of a food matrix and they can provide information on nutritional properties of food and the means to optimize selected technological processes. Furthermore, the levels of carbohydrate and organic acid are important to monitor bacterial growth and activity. Actually, these compounds can be quantified by several methods including high‐performance liquid chromatography (HPLC) and gas chromatography (GC). High‐performance liquid chromatography has been widely used to analyze carbohydrates and nonvolatile organic acids, while gas chromatography has been used to determine the volatile organic acids in complex matrices. This contribution provides an overview of chromatographic methods (HPLC and GC) used to analyze carbohydrates and organic acids in foods of animal origin.     

Microbiological and Sensorial Quality Assessment of Ready-to-Cook Seafood Products Packaged under Modified Atmosphere

ABSTRACT:  The effects of modified atmosphere packaging (MAP) (30:40:30 O₂:CO₂:N₂ and 5:95 O₂:CO₂) on the quality of 4 ready-to-cook seafood products were studied. In particular, the investigation was carried out on hake fillets, yellow gurnard fillets, chub mackerel fillets, and entire eviscerated cuttlefish. Quality assessment was based on microbiological and sensorial indices determination. Both packaging gas mixtures contributed to a considerable slowing down of the microbial and sensorial quality loss of the investigated seafood products. Results showed that sensorial quality was the subindex that limited their shelf life. In fact, based primarily on microbiological results, samples under MAP remained acceptable up to the end of storage (that is, 14 d), regardless of fish specie. On the other hand, results from sensory analyses showed that chub mackerel fillets in MAP were acceptable up to the 6th storage d, whilst hake fillets, yellow gurnard fillets, and entire cuttlefish became unacceptable after 10 to 11 d. However, compared to control samples, an increase in the sensorial shelf life of MAP samples (ranging from about 95% to 250%) was always recorded.
Practical Application: Modified atmosphere packaging (MAP) is an inexpensive and uncomplicated method of extending shelf life of packed seafood. It could gain great attention from the fish industrial sector due to the fact that MAP is a practical and economic technique, realizable by small technical expedients. Moreover, there is great attention from the food industry and retailers to react to the growing demand for convenience food, thus promoting an increase in the assortments of ready-to-cook seafood products.     

Robust nonlinear motion control for AUVs

We show how an efficient nonlinear controller for a general model of autonomous underwater vehicles (AUVs) dynamics, with uncertainties and external disturbances, can be designed by means of Lyapunov techniques. The control task we consider consists of tracking a given reference trajectory. As part of the design strategy, both model uncertainties and external disturbances physically corresponding to the effect of an underwater current are represented as a bounded perturbation of a nominal model of the vehicle dynamics     

Nitric oxide reduces nontransferrin-bound iron transport in HepG2 cells

Nitric oxide (NO) donors S-nitroso-N-acetylpenicillamine (SNAP) and sodium nitroprusside (SNP) modulate iron regulatory protein (IRP) activity and may, therefore, affect iron uptake through transferrin receptor expression. However, iron also enters the cell as nontransferrin-bound iron (NTBI), and the aim of this study was to evaluate the effects of NO donors on NTBI transport in HepG2 cells, a model of liver physiology. Incubation with SNP and SNAP led to a time- and concentration-dependent reduction in Fe3+ and Fe2+ uptake, thus indicating an effect on the transporter rather than on the reductase. In terms of Fe2+ uptake, no variations in the Michaelis-Menten constant (Km) and a reduction in maximum uptake (Vmax) (50, 33, and 16.6 fmol/microgram protein/min in control, SNP-, and SNAP-treated cells, respectively) were detected, which suggested a decrease in the number of putative NTBI transport protein(s). Gel shift assays showed that IRP activity was reduced by SNP and slightly increased by SNAP. Northern blot analysis of transferrin receptor messenger RNA (mRNA) levels showed variations similar to those observed for IRPs, but both NO donors increased L-ferritin mRNA levels and had no effect on the stimulator of Fe transport (SFT) mRNA. In conclusion, NO donors significantly reduce NTBI transport in HepG2 cells, an effect that seems to be IRP and SFT independent. Moreover, the reduction in NTBI uptake after NO treatment suggests that this form of iron may play a minor role in the increased hepatic iron stores observed in inflammation or that other liver cells are more involved in this pathological condition.     

Stereospecific distribution of fatty acids in triacylglycerols of olive oils

The positional distribution of fatty acids (FA) in triacylglycerols (TAG) of 47 virgin olive oils from diverse cultivars grown in distinct areas of North‐Eastern Italy was studied. Few data were previously available on oils from these geographical areas. The effects of climatic and geographical conditions on the stereospecific distribution of TAG in olive oil were confirmed. Moreover, the results of the stereospecific analysis were used to evaluate the preferential esterification position of each FA on the basis of the degree of unsaturation and the chain length. The data of the stereospecific analysis of olive oil TAG can contribute to the determination of the selectivity of olive fruit acyltransferases for distinct FA.     

Preferred strategies for secondary infrainguinal bypass: lessons learned from 300 consecutive reoperations

PURPOSE: To determine the optimal surgical strategies in reoperative infrainguinal bypass, we reviewed our results in 300 consecutive secondary bypasses in 251 patients operated on between Jan. 1, 1975, and Nov. 1, 1993. METHODS: There were 168 men (67%) and 83 women (33%), with a mean age of 64.8 years and a typical distribution of risk factors including smoking (76.4%), diabetes (33.7%), and coronary artery disease (47.1%). The indications for surgery were limb-threatening ischemia in 83.5% and severe claudication in 16.5% of patients. The majority of conduits (n = 213) were autogenous vein and were composed of a single segment of greater saphenous vein in 121 bypasses (57%) and various alternative veins including composite, arm, and lesser saphenous vein in 92 bypasses (43%). Prosthetic conduits included 69 polytetrafluoroethylene, 16 umbilical vein, and two Dacron grafts. RESULTS: There was one perioperative death (0.3%) and a 25% total morbidity rate including a 1.7% myocardial infarction rate. There was a 28.6% early (< 30 days) graft failure and 10.7% early amputation rate for prosthetic bypass grafts compared with 13.6% early graft failure and 5.6% early amputation rates for vein grafts. Autogenous vein bypasses had higher 5-year secondary patency rates than had prosthetic grafts (51.5% +/- 4.6% vs 27.4% +/- 6.1%, p < 0.001). Results with autogenous vein bypass improved significantly from the 1975 to 1984 to the 1985 to 1993 interval with 5-year secondary patency rates increasing from 38.3% +/- 6.9% to 59.1% +/- 5.8% (p = 0.017) and 5-year limb-salvage rates increasing from 40.4% +/- 7.6% to 72.4% +/- 6.6% (p < 0.001). Vein grafts to the popliteal and tibial outflow levels had equivalent long-term results. Vein grafts completed for claudication demonstrated results superior to those for limb salvage, with a 5-year secondary patency rate of 75.8% +/- 8.1% versus 52.3% +/- 7.9% (p = 0.048). Secondary autogenous vein bypass grafting performed after early primary graft failure (< 3 months) did particularly poorly, with only a 27.2% +/- 7.7% 4-year secondary patency rate. Greater saphenous veins tended to perform better than alternative vein bypasses, with a 5-year secondary patency rate of 68.5% +/- 6.0% compared with 48.3% +/- 10.5% (p = 0.09) and a 5-year limb-salvage rate of 77.8% +/- 7.4% versus 54.2% +/- 11.8% (p = 0.046). CONCLUSIONS: When patients suffer a recurrence of limb-threatening ischemia at the time of infrainguinal graft failure, aggressive attempts at secondary revascularization with autogenous vein are warranted based on the low surgical morbidity and mortality rates and the improved patency and limb salvage rates that are currently attainable.