In vitro digestion of beef and vegan burgers cooked by microwave technology: Effects on protein and lipid fractions.

Commercial beef burgers and vegan analogues were purchased and, after a microwave treatment, they were submitted to an in vitro digestion (INFOGEST). Vegan cooked burgers showed similar protein content (16-17 %) but lower amounts of total peptides than beef burgers. The protein digestibility was higher in beef burgers. Peptide amounts increased during in vitro digestion, reaching similar amounts in both types of products in the micellar phase (bioaccessible fraction). The fat content in cooked vegan burgers was significantly lower than in beef burgers (16.7 and 21.2 %, respectively), with a higher amount of PUFAs and being the lipolysis activity, measure by FFA, less intense both after cooking and after the gastrointestinal process. Both types of cooked samples showed high carbonyl amounts (34.18 and 25.51 nmol/mg protein in beef and vegan samples, respectively), that decreased during in vitro digestion. On the contrary, lipid oxidation increased during gastrointestinal digestion, particularly in vegan samples. The antioxidant capacity (ABTS and DPPH) showed higher values for vegan products in cooked samples, but significantly decreased during digestion, reaching similar values for both types of products.

Fat reduced cookies using an olive oil-alginate gelled emulsion: Sensory properties, storage stability and in vitro digestion.

Reformulated cookies substituting 100 % butter by an olive oil-alginate gelled emulsion containing 40 % olive oil were elaborated with and without antioxidant, and their nutritional and sensory properties were assessed. Moreover, their performance during in vitro digestion as well as their oxidative stability during storage (21 days) were studied. Reformulated cookies showed a lower fat content (a decrease of 40 %), being this fraction mostly unsaturated (70 % lower saturated fat), in comparison with conventional cookies. Instrumental measures showed higher values for hardness with reformulation, which tends to equalize during storage. Reformulated cookies had good general sensory acceptability, although lower than control ones. Regarding oxidative stability, increases in malondialdehyde were observed in all formulations during storage, but not representing an oxidation problem (<1.5 nmol/g cookies). In vitro digestion assay promoted oxidation, but the use of antioxidants seemed to have a mitigating effect. Also, it seemed that the bioaccessibility of fatty acids after in vitro digestion was higher in the reformulated products (35-40 %) than in the control ones (10-25 %).

Correlation between serum content of the main COPs (cholesterol oxidation products) from autoxidation and cardiovascular risk factors.

BACKGROUND/AIMS: Risk factors for cardiovascular disease (CVD) have been proven to be associated with an increased oxidative stress. Several studies have considered cholesterol oxidation products (COPs) as specific in vivo markers of oxidative stress. The aim of this study was to investigate the association between the levels of COPs derived from autoxidation processes and established cardiovascular risk factors, comparing the levels of serum COPs in subjects with or without showing values out of the reference ranges. METHODS: It was a cross-sectional study in which 88 subjects were recruited and individual and total COPs from autoxidation origin was analyzed in serum by GC-MS. The simultaneous correlation of COPs with different CVD risk factors have been analyzed. RESULTS AND DISCUSSION: A great variability of total COPs concentrations were found. Subjects presented total COPs values from 0.091 to 2.052 µg/mL. Total COPs were significantly higher (p < 0.05) in patients with hypertriglycerolemia, hypertension, diabetes and overweight/ obesity status compared to those subjects who did not present those CVD risk factors. Moreover, 7α and 7ß hydroxycholesterol and 7-ketocholesterol were significantly higher (p < 0.05) in patients with hypertension and diabetes. No significant differences in total COPs were found between patients with and without hypercholesterolemia. CONCLUSIONS: The obtained results showed that the analyzed COPs correlate well with at least 4 out of 6 risk factors of development of CVD.

Oxysterols: A world to explore.

Oxysterols (oxidized derivatives of cholesterol and phytosterols) can be generated in the human organism through different oxidation processes, some requiring enzymes. Furthermore, oxysterols are also present in food due to lipid oxidation reactions caused by heating treatments, contact with oxygen, exposure to sunlight, etc., and they could be absorbed from the diet, at different rates depending on their side chain length. In the organism, oxysterols can follow different routes: secreted into the intestinal lumen, esterified and distributed by lipoproteins to different tissues or degraded, mainly in the liver. Cholesterol oxidation products (COPs) have shown cytotoxicity, apoptotic and pro-inflammatory effects and they have also been linked with chronic diseases including atherosclerotic and neurodegenerative processess. In the case of phytosterol oxidation products (POPs), more research is needed on toxic effects. Nevertheless, current knowledge suggests they may also cause cytotoxic and pro-apoptotic effects, although at higher concentrations than COPs. Recently, new beneficial biological activities of oxysterols are being investigated. Whereas COPs are associated with cholesterol homeostasis mediated by different mechanisms, the implication of POPs is not clear yet. Available literature on sources of oxysterols in the organism, metabolism, toxicity and potential beneficial effects of these compounds are reviewed in this paper.

[Assessment of calf circumference as an indicator of the risk for hyponutrition in the elderly]. / Valoración de la circunferencia de la pantorrilla como indicador de riesgo de desnutrición en personas mayores.

BACKGROUND: Undernutrition is a very common situation among elderly, that is associated with increased morbidity and mortality rates. On the other hand, calf circumference (CC) is a direct anthropometric measurement, related to fat free mass. An early detection of an elderly undernutrition situation, based on CC assessment, could contribute to prevent its development and consequences. OBJECTIVE: To analyse the relationship between CC and a possible undernutrition situation, based on the application of the Mini Nutritional Assessment (MNA) test, among Spanish subjects of 65 or more years old, including the gender and age influences. SUBJECTS AND METHODS: A cross-sectional study was carried out to assess the nutritional situation of an ambulatory population, from every area of Spanish geography (n = 22007), using the questionnaire MNA. Every subject surveyed was 65 or more years old when the test was done. RESULTS: There were statistically significant differences between subjects with a CC < 31 cm and those with CC >or= 31 cm, both men and women, in weight, height, body mass index (BMI), MNA total score and undernutrition classification. On the other hand, it was found that those elders with lower CC showed a higher undernutrition risk, both men and women, in every age range studied. CONCLUSIONS: It does exit an association between CC of Spanish subjects of 65 or more years old and the risk of developing undernutrition. That association is similar among men and women, and in all age ranges.

Nutritional assessment interpretation on 22,007 Spanish community-dwelling elders through the Mini Nutritional Assessment test.

OBJECTIVES: To evaluate the prevalence of undernutrition among community-dwelling elderly people in Spain using the Mini Nutritional Assessment (MNA) and to analyse its distribution according to age, gender and residence region. DESIGN: Cross-sectional study assessing the nutritional status of elderly persons through both the short form and the full version of the MNA test. SETTING: Pharmacy offices across the whole country (Spain) were enrolled to recruit participants. SUBJECTS: A total of 22 007 participants (8014 men and 13 993 women), aged >or=65 years, assessed during the last two months of 2005. RESULTS: According to MNA screening, 4.3 % subjects were classified as undernourished (MNA score <17) and 25.4 % were at risk of undernutrition (MNA score >or=17 to

Food consumption analysis in spanish elderly based upon the mini nutritional assessment test.

BACKGROUND/AIMS: Aged people are an increasing population group worldwide, and nutritional impairments may contribute to additional health problems. The characterization of food consumption of elderly people is a good approach to implementing adequate nutritional policies in order to improve their nutritional status. The aim of this study was to describe and analyze specific aspects of food intake based upon the Mini Nutritional Assessment (MNA) test in a representative country sample. METHODS: The survey consisted of a cross-sectional study assessing the nutritional status of 22,007 Spanish people aged 65 years or older using the MNA test. These data, including dietary information, were obtained by health professionals specifically trained to carry out the questionnaire. A multiple regression analysis was used to evaluate the contributing impact of the diet-related MNA questions on the total MNA score. RESULTS: Differences in the food choices between men and women were found, but not in the mode of feeding. Obese and non-obese individuals, categorized by a body mass index (BMI) more or less than 30, showed similar intake patterns of protein-rich foods, but differences in fruits, vegetables and fluids. On the other hand, undernourished and non-undernourished subjects, according to the MNA criteria, revealed different food consumption. Loss of appetite and mode of feeding were the items with the highest influence the MNA total score. CONCLUSIONS: While age, gender and BMI considered together are responsible for 11.3% of the total MNA score, dietary-related items can predict the 62.4% of the total MNA classification in the overall elderly Spanish population.

Inhibition of serum cholesterol oxidation by dietary vitamin C and selenium intake in high fat fed rats.

Cholesterol oxidation products (COPs) have been considered as specific in vivo markers of oxidative stress. In this study, an increased oxidative status was induced in Wistar rats by feeding them a high-fat diet (cafeteria diet). Another group of animals received the same diet supplemented with a combination of two different antioxidants, ascorbic acid (100 mg/kg rat/day) and sodium selenite (200 microg/kg rat/day) and a third group fed on a control diet. Total and individual COPs analysis of the different diets showed no differences among them. At the end of the experimental trial, rats were sacrificed and serum cholesterol, triglycerides and COPs were measured. None of the diets induced changes in rats body weight, total cholesterol and triglycerides levels. Serum total COPs in rats fed on the high-fat diet were 1.01 microg/ml, two times the amount of the control rats (0.47 microg/ml). When dietary antioxidant supplementation was given, serum total COPs concentration (0.44 microg/ml) showed the same levels than those of the rats on control diet. 7beta-hydroxycholesterol, formed non-enzymatically via cholesterol peroxidation in the presence of reactive oxygen species, showed slightly lower values in the antioxidant-supplemented animals compared to the control ones. This study confirms the importance of dietary antioxidants as protective factors against the formation of oxysterols.

Enhancement of the nutritional status and quality of fresh pork sausages following the addition of linseed oil, fish oil and natural antioxidants.

Fresh pork sausages (pork shoulder, pork back fat, water, rusk and seasoning) were manufactured where 15% of the pork back fat was substituted with linseed oil (LO) or fish oil (FO). Green tea catechins (GTC) and green coffee antioxidant (GCA) were added to both LO (LGTC 200 and LGCA 200) and FO (FGTC 200 and FGCA 200) substituted sausages at a level of 200mg/kg. Raw and cooked pork sausages were either over-wrapped with oxygen permeable film (aerobic storage) or stored in modified atmosphere packages (MAP) containing 80% O(2):20% CO(2) or 70% N(2):30% CO(2), respectively for 7 days at 4°C. Effects on fatty acid profiles, lipid oxidation, colour and sensorial properties were investigated. α-Linolenic acid increased from 1.34% (control) to 8.91% (LO) and up to 11.2% (LGTC 200 and LGCA 200). Addition of fish oil increased levels of EPA from 0.05% (control) to 2.83% (FO), 3.02% (FGTC 200) and 2.87% (FGCA 200) and DHA levels increased from 0.04% (control) to a maximum of 1.93% (FGTC 200). Lipid oxidation was low in raw and cooked linseed oil containing sausages. GTC (200mg/kg) significantly (P<0.05) reduced lipid oxidation in raw fish oil containing sausages after 7 days of storage. Colour parameters in raw pork sausages were unaffected by the packaging atmosphere. L(∗) lightness values were lower (P<0.05) in LGTC 200 and a(∗) redness values lower (P<0.05) in LGTC 200 and FGTC 200 after 7 days of storage. Sensory scores of cooked pork sausages were unaffected by linseed oil addition. Flavour and overall acceptability scores in cooked fish oil containing sausages were improved by GTC addition. Results obtained demonstrate potential for the production of nutritionally enhanced fresh pork sausages.

[Functional components in fish and algae oils]. / Componentes funcionales en aceites de pescado y de alga.

An important area of the development of new functional foods is facussed on finding or applying food components which favour achieving a healthier lipid profile in the organism. The objective of this work was to carry out the characterisation of the lipid fraction of two oils, fish oil and algae oil, to evaluate their potential use as functional ingredients, in relation to the high molecular weight fatty acid content and the presence of sterols and other components of the unsaponificable fraction. Both oils showed a lipid fraction rich in high molecular weight polyunsaturated omega-3 fatty acids, containing a 33.75% in the fish oil and a 43.97% in the algae oil. Eicosapentaenoic acid was the major fatty acid in fish oil, whereas docosahexaenoic was the most abundant fatty acid in algae oil. The omega-6/omega-3 ratio was lower than 0.4 in both oils. In the unsaponificable fraction, algae oil had a Mold lower cholesterol content and a higher proportion of squalene than fish oil. The phytosterol content was significantly higher in the algae oil.

Nutritional and sensory properties of dry fermented sausages enriched with n-3 PUFAs.

Enrichment of dry fermented sausages with n-3 fatty acids through a partial substitution of pork backfat by deodorised fish oil resulted in improved nutritional properties with regard to conventional sausages, without affecting sensory properties and oxidation status. The developed products supplied 0.64g EPA/100g and 0.46g DHA/100g product, and showed PUFA+MUFA/SFA ratio of 1.76 and n-6/n-3 ratio of 2.97. No signs of oxidation were found in any type of sausages, control and modified. None of the dienals and trienals reported as secondary lipid oxidation products and typical for fish oil were detected in the modified sausages. Instrumental colour differences were detected, however, without relevance in the sensory analysis. The sensory evaluation panel did not find differences in general acceptability. The modified dry fermented sausages can be considered a technologically viable functional food.

Stability of linseed oil and antioxidants containing dry fermented sausages: A study of the lipid fraction during different storage conditions.

Different packaging conditions (aerobic, vacuum and modified atmosphere) were evaluated in order to study the stability of the lipid fraction of dry fermented sausages manufactured with a partial substitution of pork backfat by linseed oil and antioxidants. After 5 months of storage, α-linolenic acid was better preserved by vacuum and MAP (7.32 and 7.74g/100g fatty acids, respectively) than in aerobic conditions (6.15g/100g fatty acids), without significant differences to values obtained after 2 months of storage for this acid. At the end of the storage, (n-6)/(n-3) fraction in sausages with linseed oil was in all cases lower than 3, in contrast to values obtained for control products that were all higher than 15. Better PUFA/SFA ratios were also observed in modified sausages (0.6-0.7g/100g fatty acids) than control ones (0.3-0.4g/100g fatty acids). No signs of lipid oxidation measured by TBARs and peroxides were detected for modified sausages regardless the packaging system used (TBARs values lower than 0.25ppm and peroxides lower than 4meq O(2)/kg), pointing at a high effectiveness of the antioxidants. Furthermore, vacuum and MAP prevented 2,4-decadienal formation. Nutritional benefits of linseed oil and antioxidants containing products were maintained after 5 months of storage.

[Cholesterol oxidation products in fresh and frozen shrimps, raw and grilled]. / Oxidos de colesterol en langostinos frescos y congelados, crudos y a la plancha.

Cholesterol oxidation products (COPs) have been related to different toxic effects, being the atherosclerotic process one of the best known. The presence of cholesterol oxides in freshly and frozenly commercialised shrimps, both raw and grilled, was studied. The determination was made by gas chromatography-mass spectrometry (GCMS). Fresh shrimps showed significant amounts of all analysed COPs, except for 7alpha-hydroxycholesterol, accounting in total for 33.15 microg COPs/g fat. In contrast, in frozen commercialised shrimps only 7-ketocholesterol and 7beta-hydroxycholesterol were detected. These results point out the great effectiveness of the commercialisation of this type of products under freezing, in terms of to the minimisation of the COPs formation. The cooking method (grilling) increased the COPs content in both types of shrimps, reaching 55.43 microg COPs/g fat in fresh shrimps and only 13.06 microg COPs/g fat in frozen ones.

Study of the effect of different fiber coatings and extraction conditions on dry cured ham volatile compounds extracted by solid-phase microextraction (SPME).

Extraction of dry cured ham volatile compounds by solid-phase microextraction (SPME) was optimized. Different fiber coatings (carboxen/polydimethylsiloxane (CAR/PDMS), divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS), polydimethylsiloxane (PDMS), polydimethylsiloxane/divinylbenzene (PDMS/DVB)), times of extraction (15, 30, 60min) and sample preparation (ground samples and homogenates with NaCl saturated solution) were assayed. CAR/PDMS and DVB/CAR/PDMS fiber coatings extracted more than 100 volatile compounds and showed the highest area counts for most volatile compounds. CAR/PDMS coating extracted better those compounds whose Kovats index (KI) was lower than 980 (on average) and DVB/CAR/PDMS those with higher KI. Fifteen minutes of extraction provided a volatile compound profile with lower area counts for most compounds and qualitatively different to that obtained with 30 and 60min of extraction. Homogenates gave a different profile compared to ground samples, with lower total counts for most compounds but higher proportion of aldehydes, and presence of several compounds not found in ground samples.

Improvement of nutritional properties of Chorizo de Pamplona by replacement of pork backfat with soy oil.

Dry fermented sausages with a partial substitution of 15, 20 and 25% of pork backfat by pre-emulsified soy oil were prepared. No differences were detected in the water, protein and fat content between control and modified sausages. Cholesterol amount scarcely decreased in the modified sausages (92.96 mg/100 g product in control sausages, 87.71 mg/100 g in sausages prepared with 25% of substitution). No increase in oxidation was detected through chemical or sensory analysis in modified sausages. Saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) in control products were 37.83 and 45.78 g/100 g of total fatty acid, respectively, decreasing in the modified formulations, to 32.81 and 42.09 g/100 g of total fatty acid in the 25% replacement products, respectively. Polyunsaturated fatty acids (PUFA) increased from 15.22 (control) to 23.96 g/100 g of total fatty acid (25% product) due to the significant increase in linoleic and α-linolenic acids when soy oil was added. In relation to texture profile analysis (TPA), hardness and springiness did not show significant differences among products. The instrumental measured colours were comparable with that of commercial products. Sensory evaluation of most of the modified sausages did not show significant differences with regard to the control.

Effect of fat level and partial replacement of pork backfat with olive oil on processing and quality characteristics of fermented sausages.

Six formulations of dry fermented sausages were produced in three replications with three initial fat levels (30, 20 and 10%) and two levels (0 and 20%) of pork backfat replacing olive oil. After 4 weeks of fermentation and ripening the fat content of the treatments with 30, 20 and 10% fat level ranged from 38.86 to 43.60%, 25.56 to 26.86% and 19.01 to 20.14%, respectively. Fat level affected (P<0.05) the weight losses, the chemical composition, the Gram -ve bacterial count, the lightness, the texture and the appearance of fermented sausages. Replacing 20% of pork backfat by olive oil affected (P<0.05) the lightness and yellowness of sausages. Fat-reduced sausages without olive oil and low-fat sausages with olive oil had the highest score for odour and taste. However, the appearance of fat-reduced sausages was just acceptable while that of low-fat sausages was unacceptable, because the surface was intensively wrinkled and case hardening had developed. Further research is needed to improve the appearance of these sausages.

Oxidation process affecting fatty acids and cholesterol in fried and roasted salmon.

Salmon was processed by three different culinary techniques: pan-frying with olive oil, pan-frying with soya oil, and roasting. Roasting did not modify the fat content from that of raw samples. Frying increased the fat content 2-fold, with no difference between samples fried with different oils. Total cholesterol oxidized products (COPs) were 0.74, 2.98, 3.35, and 7.38 microg/g fat in raw, fried with olive oil, fried with soya oil, and roasted salmon, respectively, which represent 0.01, 0.08, 0.09, and 0.15% of cholesterol. A significant correlation (r = 0.902, < or = 0.01) was found between acidity index and total COPs. The most abundant COPs were 7-ketocholesterol, which appeared in all the samples, and cholestanetriol (one of the most citotoxic COP), which appeared only in cooked samples (1.05-1.33 microg/g fat). All cooked samples supplied more omega-6 polyunsaturated fatty acids (PUFAs) than raw samples and showed higher omega-6/omega-3 ratios. Roasted salmon showed the lowest omega-3 content and the highest PUFAs/(SFAs)-C18:0 and MUFAs+PUFAs/(SFAs-C18:0) ratios.

Fatty acid modifications and cholesterol oxidation in pork loin during frying at different temperatures.

The effect of frying with sunflower oil for 4 min at different temperatures (160, 170, and 180 degrees C) on fatty acids and cholesterol of pork loin meat was studied. Total fat content increased from 5.6% in fresh loin to 7.3, 7.8, and 12.1% at 160, 170, and 180 degrees C, respectively. Interactions with culinary fat gave rise to a significant increase in unsaturated acids/saturated acids and polyunsaturated acids/saturated acids ratios, which could be considered an advantage from a nutritional point of view. Less than 1 ppm (microg/g of sample) of cholesterol oxidation products was detected in fresh loin, whereas fried loin pork contained between 8.58 and 10.89 ppm. 7-Ketocholesterol (5.99 to 8.47 ppm in fried samples) and 7beta-hydroxycholesterol (1.43 to 2.55 ppm in fried samples) were the main cholesterol oxidation products. Cholestanetriol was not detected in any sample, and small quantities of 25-hydroxycholesterol and 5,6alpha-epoxycholesterol were found in the fried sample.

Postprandial de novo lipogenesis and metabolic changes induced by a high-carbohydrate, low-fat meal in lean and overweight men.

BACKGROUND: Adjustments of carbohydrate intake and oxidation occur in both normal-weight and overweight individuals. Nevertheless, the contribution of carbohydrates to the accumulation of fat through either reduction of fat oxidation or stimulation of fat synthesis in obesity remains poorly investigated. OBJECTIVE: The objective of this study was to assess the postprandial metabolic changes and the fractional hepatic de novo lipogenesis (DNL) induced by a high-carbohydrate, low-fat meal in lean and overweight young men. DESIGN: A high-carbohydrate, low-fat meal was administered to 6 lean and 7 overweight men after a 17.5-h fast. During the fasting and postprandial periods, energy expenditure (EE), macronutrient oxidation, diet-induced thermogenesis, and serum insulin, glucose, triacylglycerol, and fatty acids were measured. To determine DNL, [1-13C]sodium acetate was infused and the mass isotopomer distribution analysis method was applied. RESULTS: After intake of the high-carbohydrate meal, the overweight men had hyperinsulinemia and higher fatty acid and triacylglycerol concentrations than did the lean men. The overweight group showed a greater EE, whereas there was no significant difference in carbohydrate oxidation between the groups. Nevertheless, the overweight men had a marginally higher protein oxidation and a lower lipid oxidation than did the lean men. DNL was significantly higher before and after meal intake in the overweight men and was positively associated with fasting serum glucose and insulin concentrations. Furthermore, postprandial DNL was positively correlated with body fat mass, EE, and triacylglycerol. CONCLUSION: After a high-carbohydrate, low-fat meal, overweight men had a lower fat oxidation and a higher fractional hepatic fat synthesis than did lean men.

Calcium ascorbate as a potential partial substitute for NaCl in dry fermented sausages: effect on colour, texture and hygienic quality at different concentrations.

A control product (2.6% NaCl) and different treatments with reduced levels of salt (1, 2.3% NaCl; 2, 2.0% NaCl; 3, 1.7% NaCl; 4, 1.4% NaCl) and increased amounts of calcium ascorbate with an equivalent ionic strength to that of the control were assayed. The percentages of reduction of sodium content in relation to the control were 15, 24, 37 and 45% and the supply of calcium was 26, 33, 42 and 50% of the Recommended Dietary Allowance (RDAs established by NRC, US) for treatments 1, 2, 3 and 4, respectively. Partial substitution of NaCl by calcium ascorbate caused higher acidification related with the higher lactic acid bacteria development and probably with the presence of calcium. The instrumental measurement of colour gave rise to some significant differences especially with the highest amount of calcium ascorbate (treatment 4), giving rise to significant higher a* and b* values and lower L* values in relation to the control. Treatments 2, 3 and 4 lead to products with lower hardness and gumminess values than the control. No problems related to the hygienic quality were observed.