Current and New Insights on Delivery Systems for Plant Sterols in Food.

Plant sterols are minor bioactive components of food lipids, which are often used for the formulation of functional foods due to their cholesterol-lowering properties. However, they have low solubility and tend to crystallize, which may affect their biological effects, the sensory profile of the sterol-enriched food, and its consumer acceptability. Moreover, due to the unsaturated structure of sterols, they are susceptible to oxidation, so different encapsulation systems have been developed to improve their dispersibility/solubility, stability, delivery, and bioaccessibility. This chapter provides an overview of the main encapsulation systems currently used for plant sterols and their application in model and food systems, with a particular focus on their efficiency and impact on sterol bioaccessibility.

Effects of sous vide vs grilling methods on lamb meat colour and lipid stability during cooking and heated display.

The present study compared the effect of grilling (150 °C until 72 °C core temperature) and sous-vide (SV) cooking (75 °C for 35 min in a water bath under vacuum) on lamb patties immediately after cooking and after 4 h display at 65 °C. Both methods produced patties with similar (P > 0.05) weight loss, and moisture and fat contents. SV-cooking prevented (P < 0.05) the formation of thiobarbituric acid reactive substances (TBARS) and oxysterols compared to grilled patties, which showed a larger proportion of highly peroxidisable polyunsaturated fatty acids. Heated display induced dehydration, surface darkening and a reduction in the hexanal/3-methylbutanal ratio, suggesting the progression of Maillard reactions. Moreover, TBARS and some lipid oxidation-derived volatiles increased (P < 0.001), while cooked-meat aroma compounds were reduced (P < 0.001). SV-cooking inhibited (P < 0.05) the formation of malondialdehyde, and 7α- and 7ß-hydroxycholesterol, and lowered the cholesterol oxidation ratio during heated display. Overall, SV-cooking may be considered a healthier way of cooking when lamb meat is to be kept warm for considerable periods before consumption.

Evaluation of Breed and Parity Order Effects on the Lipid Composition of Porcine Colostrum.

Porcine colostrum lipid classes and fatty acids (FA) were characterized in 6 pools (from 69 samples) from 3 sow breeds (Italian Large White, Italian Landrace, and Italian Duroc) and different parity orders (only Large White). Triacylglycerols (TAG; 94.44 expressed as g/100 g of fat) were the most abundant lipid class, followed by diacylglycerols (DAG; 3.36 g/100 g of fat), free fatty acids (FFA; 0.98 g/100 g of fat), and cholesterol (0.84 g/100 g of fat). The main FAs found in swine colostrum were palmitic (27.29%, expressed as g/100 g of total FA), oleic (28.81%), and linoleic (23.39%) acids. Both the breed of sow and parity order affected the FA and lipid composition. The results suggest that the FA composition of swine colostrum is similar to that of human colostrum and could represent a new source of nutrients for human infants, after further assessment of hygienic and quality aspects. The swine model could be an opportunity for a better understanding of colostrum effects on newborns.

Comparison of meat quality characteristics and oxidative stability between conventional and free-range chickens.

The aim of this research was to evaluate quality traits and oxidative stability of meat products from free-range (FR) and conventionally (C) raised chickens as they actually reach consumers in the Italian retail market. Free-range female and male chickens (n = 1,500 + 1,500), medium growing ISA strain, were raised under commercial conditions for 56 (1.8 kg of live weight) and 70 d (3.1 kg of live weight), respectively; C female and male birds (n = 5,000 + 5,000) were a fast growing hybrid (Ross 708) and were separately raised for 39 (1.9 kg of live weight) and 50 d (3.1 kg of live weight), respectively. A total of 96 chickens (equally divided by production system and sex) were slaughtered in 2 separate sessions to obtain the main 2 commercial categories (rotisserie and cut-up, respectively). After slaughtering, 12 carcasses of each treatment group were randomly selected and used to assess quality properties, chemical composition, and oxidation stability of breast and leg meat. The C birds had dramatic higher carcass and breast meat yield, whereas FR had higher wing and leg yields. The FR birds exhibited higher water holding capacity in both breast and leg meat. Although shear force did not differ in breast meat, legs from FR birds were tougher. Fatty acid composition of FR breast and thigh meat of both categories were characterized by a higher polyunsaturated fatty acid n-6-/n-3 ratio. In general, a low lipid oxidation level (peroxide value < 1.3 mEq O2/kg of lipid and TBA reactive substances < 0.2 mg malondialdehyde/kg of sample) was found in breast and legs, regardless of the commercial category. However, the C system significantly increased peroxide value in rotisserie thigh meat, whereas FR led to a significantly higher TBA reactive substances in breast meat. Our results demonstrated that free range can modify the properties of chicken meat and also highlighted the importance of the bird genetic background to select nutritional strategies to improve meat quality traits and oxidative stability in poultry.

Fatty acid composition, oxidation status and volatile organic compounds in "Colonnata" lard from Large White or Cinta Senese pigs as affected by curing time.

The aim of the present paper was to evaluate the fatty acid composition, lipolysis, lipid oxidation and volatile organic compounds (VOCs) in Colonnata lard from Large White (LW) or Cinta Senese (CS) pigs during one-year of curing. CS lard contained higher amounts of unsaturated fatty acids than that from LW, due to the different rearing and feeding systems. Despite higher lipolysis in CS backfat during the curing period, the rate of fatty acid and cholesterol oxidation was higher in LW. The amount of cholesterol oxidation products (COPs) and thiobarbituric acid reactive substances (TBARs) significantly decreased after 3 months of curing, regardless of the type of lard. VOCs composition of lard was affected by curing time, but not by breed. While volatile fatty acid oxidation products (mainly aldehydes) were present at the beginning of curing, subsequently other volatile compounds (such as sulphur compounds and terpenes) that derived from ingredients used for lard production, increased in the samples.

Assessment of in vitro removal of cholesterol oxidation products by Lactobacillus casei ATCC334.

Cholesterol oxidation products (COPs) are a group of compounds formed during processing and storage of foods from animal origin. After ingestion, COPs are absorbed in the intestine and can be distributed to serum and various tissues, potentially promoting a variety of toxic effects. Therefore, inhibition of their intestinal absorption may contribute to reduce the health risks associated with dietary intake of COPs. Some studies have shown that drugs and dietary compounds may inhibit the intestinal absorption of dietary COPs. However, proven cholesterol- and/or food toxins-binding lactic acid bacteria have not been previously evaluated as potential COPs removal agents. The aim of this study was to assess the ability of Lactobacillus casei ATCC334 to remove COPs in aqueous solution. Results showed the ability of both growing and resting cells to remove COPs (ca. 30-60%). All COPs-bacterium interactions were specific and partly reversible, being resting cells the most efficient for COPs removal in a ranking order of 7-KC > 7α-OH/7ß-OH > triol > 5,6ß-EP > 5,6α-EP > 25-OH. Binding to the cell wall and/or cell membrane incorporation appears to be the most likely mechanisms involved on COPs removal by L. casei ATCC 334.

Enhanced methane production in a two-phase anaerobic digestion plant, after CO2 capture and addition to organic wastes.

Cost-effective technologies are needed to reach the international greenhouse gas (GHG) reduction targets in many fields, including waste and biomass treatment. This work reports the effects of CO(2) capture from a combustion flue gas and its use in a newly-patented, two-phase anaerobic digestion (TPAD) process, to improve energy recovery and to reduce CO(2) emissions. A TPAD process, fed with urban wastewater sludge, was successfully established and maintained for several months at pilot scale. The TPAD process with injection of CO(2) exhibits efficient biomass degradation (58% VSS reduction), increased VFA production during the acidogenic phase (leading to VFA concentration of 8.4 g/L) and high biomethane production (0.350 S m(3)/kg(SSV); 0.363 S m(3)/m(3)(react) · d). Moreover, CO(2) intake in the acid phase has a positive impact on the overall GHG balance associated to biomethane production, and suggests an improved solution for both emission reduction and biomass conversion into biomethane.

Suitability of saturated aldehydes as lipid oxidation markers in washed turkey meat.

The aim of this study was to evaluate the suitability of saturated aldehydes as lipid oxidation markers in washed turkey muscle, by means of headspace solid phase microextraction-gas chromatography (HS-SPME-GC); the results were compared with the widely used thiobarbituric acid-reactive substances (TBARs) method. Changes in TBARs, propanal and hexanal concentrations were determined over time in a model system consisting of turkey muscle washed with a sodium phosphate buffer (pH 5.6). To stop oxidation from occurring during analysis, an antioxidant mixture (EDTA, trolox and propyl gallate) was added immediately before analyses. After antioxidant addition, propanal and TBARs concentrations did not increase during 8h of further storage, while an unexpected decrease in hexanal was observed. To determine if aldehydes were interacting with washed turkey muscle, hexanal and propanal were added to either phosphate buffer or washed muscle and concentrations were monitored for 24h. Neither propanal nor hexanal decreased in the phosphate buffer over time, but the headspace concentration of propanal and hexanal in washed turkey muscle were markedly lower (76% and 96%, respectively) at time zero and continued to decreased up to 24h of storage. Because of this decrease in headspace aldehyde concentrations, TBARs were found to be a more sensitive and accurate marker of oxidative deterioration in washed turkey muscle.

Magnetic resonance spectroscopy and chromatographic methods identify altered lipid composition in human renal neoplasms.

We report on the characterization of the lipid obtained from cortical and medullary normal human kidney tissue, benign renal neoplasms (oncocytoma) and 2 different types of malignant renal neoplasms (chromophobic cell carcinoma and clear cell carcinoma). The total lipid fractions were analyzed by 13C magnetic resonance spectroscopy and thin-layer chromatography, whereas the composition of the total fatty acids and the content of total cholesterol were determined by gas chromatography. alpha-Tocopherol was detected and quantified by high-performance liquid chromatography. The spectroscopic and chromatographic analysis revealed significant differences in the renal tissues examined. It was confirmed that cholesteryl esters (mainly oleate) are typical of clear cell renal carcinomas. Their potential role as prognostic and diagnostic factors is discussed, with particular emphasis on its capability to indicate the tumor diffusion in healthy renal parenchyma. alpha-Tocopherol is prevalent in clear cell carcinoma and it is present in nearly the same low amounts in cortex, medulla and chromophobic cell renal carcinoma. Q10 coenzyme and dolichols were detected by thin-layer chromatography and they are present in significant amounts in the cortex and the benign oncocytoma. Great variations were found in the distribution of saturated and unsaturated fatty acids, especially in the docosapentaenoic, docosahexaenoic and arachidonic acids and the corresponding omega-6/omega-3 fatty acids ratio.

Chromatographic analysis of unsaponifiable compounds of olive oils and fat-containing foods.

The analysis of the "minor components" present in food lipids is usually hampered by the large diversity of compounds found in this fraction. High-purity degree reagents and solvents, good collection techniques and highly sensitive analysis are required in order to accurately identify and quantify these components. Chromatographic techniques have proven to be particularly suitable for these determinations, especially capillary gas chromatography. This study reports several analytical cases of the main classes of components of the unsaponifiable matter obtained from olive oils or food matrices.

Effect of different cooking methods on some lipid and protein components of hamburgers.

The effects of different cooking methods on the lipid and protein fractions of hamburger were evaluated. The lipid component was subjected to the following analyses: peroxide value; p-anisidine; total and free fatty acids; cholesterol and its oxidation products (quantified as 7-ketocholesterol). Lysinoalanine (LAL), free amino acids and D-amino acids (D-AA) were also determined in the protein fraction. All results were compared with a raw control. No significant differences were found among the cooking treatments with respect to D-AA and LAL. The degree of proteolysis, lipolysis and lipid oxidation varied depending on the treatment conditions. Regarding cholesterol oxidation, the combination of roasting and microwave heating caused more oxidation than the other treatments. The raw meat, however, showed an advanced degree of oxidation (25.2 ppm of total 7-ketocholesterol/120 g ground meat).