Influence of whole and fresh-cut mango intake on plasma lipids and antioxidant capacity of healthy adults

The content of antioxidant compounds and antioxidant capacity of whole and fresh-cut mango, stored for 10 days at 12 °C and 5 °C, respectively and their influence on serum antioxidant capacity and lipid profile of normolipidemic humans were studied. Whole mango (WM) had a higher content of flavonoids, ??-carotene and antioxidant capacity, determined by oxygen radical scavenging capacity, (ORAC) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays, than the fresh-cut fruit (FCM). FCM presented higher amounts of total phenols. Thirty normolipidemic volunteers, ages 20-50 years, were randomly divided into two groups (WM and FCM) 15 persons each. During 30 consecutive days volunteers from groups 1 and 2, received daily 200 g of WM or FCM, respectively. Lipid levels and antioxidant capacity in plasma were determined at 0, 15 and 30 days of the experiment. Serum triglycerides were significantly reduced after 30 days of supplementation with WM and FCM (37 and 38% respectively); VLDL levels were reduced in a similar proportion. No significant changes in other plasma lipid levels were observed. Both treatments increased plasma antioxidant capacity measured by ORAC and TEAC methods. According to the results obtained in this study, we suggest that addition of mango fruit to generally accepted healthy diets could have a beneficial effect preventing hypertryglyceridemia, and that fresh-cut processing does not affect the beneficial properties of mango.     

Study of the effect of ‘Ataulfo’ mango (Mangifera indica L.) intake on mammary carcinogenesis and antioxidant capacity in plasma of N-methyl-N-nitrosourea (MNU)-treated rats

The effect of ‘Ataulfo’ mango consumption on chemically induced mammary carcinogenesis and plasma antioxidant capacity in rats treated with N-methyl-N-nitrosourea (MNU) was studied. Mango was administered in the drinking water (0.02–0.06 g/mL) during both short-term and long-term (LT) periods to rats treated or not with MNU. Rats treated with MNU showed no differences in mammary carcinogenesis or in plasma antioxidant capacity measured by both ferric reducing/antioxidant power (FRAP) and total oxyradical scavenging capacity assays. However, in animals not treated with MNU but with a LT intake of mango the plasma antioxidant capacity as measured by the FRAP assay tended to increase in a dose-dependent manner. This suggests that mango consumption by healthy subjects may increase antioxidants in plasma.     

Cultivar relationships in mango based on fruit volatile profiles

Aroma volatiles of mango (Mangifera indica L.) determine consumer acceptability and influence selection, whilst breeding. To assess their variety, composition and possible impact on cultivar relationships, volatile blends of 22 Indian and five non-Indian cultivars were investigated using solvent extraction and gas chromatography. Totally 84 volatiles belonging to various chemical classes were detected. Based on the cumulative occurrence of members of these classes, cultivars were grouped as monoterpene or sesquiterpene dominant. α-Pinene, β-myrcene and β-caryophyllene were found in all 27 cultivars. For ordination, common compounds with high (relative) concentration provided quantitative characters, whereas the rare and lesser ones provided qualitative (binary) characters; non-Indian cultivars separated from Indian ones but displayed close relations within their groups. In conclusion, mango flavour is dominated qualitatively as well as quantitatively by terpene hydrocarbons; ancient selection of mango cultivars is hinted to be driven by different aroma characters in different parts of the world.     

Scavenger effect of a mango (Mangifera indica L.) food supplement’s active ingredient on free radicals produced by human polymorphonuclear cells and hypoxanthine–xanthine oxidase chemiluminescence systems

The in vitro antioxidant and free radical scavenging properties of a stem bark aqueous extract of mango tree (Mangifera indica L.), whose formulations are used in Cuba as food supplements under the brand name of Vimang^®, were studied. Luminol-enhanced chemiluminescence was used to elucidate the effect of this extract on the generation of reactive oxygen species in PMA- or zymosan-stimulated human polymorphonuclear leukocytes and on superoxide radicals generated in the hypoxanthine–xanthine oxidase reaction. Chemiluminescence was reduced in a dose-dependent manner at extract concentrations from 5 to 100 μg/ml, most probably by inhibiting the superoxide generation reaction. Part of this M. indica extract antioxidant activity could be ascribed to the presence of mangiferin as its main component.     

Structure-texture relationships of fresh pastes prepared from different yam (Dioscorea spp.) varieties

Yam (Dioscorea spp.) presents an important tropical food crop rich in starch. In West Africa, yam is traditionally prepared by pounding of cooked yam to obtain a dough-like paste known as pounded yam or ‘foutou’. The present investigation deals with structure-texture relationships of yam pastes as influenced by yam varieties. In general, the firmness of yam pastes prepared from D. cayenensis-rotundata was higher than that from D. alata. Difference in firmness was found to be related to the extent of cell disintegration, which was more pronounced for D. alata as assessed by light microscopy. Pronounced textural changes were measured during ageing of yam pastes, which is a consequence of the reorganization (retrogradation) of the amylose fraction. Post-harvest storage of yam tubers resulted in increased firmness and decreased adhesion properties in the pastes, but no significant influence of the storage treatment with gibberellic acid, which reduces storage losses, was detected. It is concluded that the texture of yam pastes is largely determined by the integrity of cells and the properties of the continuous starch phase.     

The effects of silage feeding on some sensory and health attributes of cow’s milk: A review

Silage has been the prevailing type of preserved forage for cattle feeding in many countries. Carry-over of some components from silage to cow’s milk has been thus of concern. Silage is a richer source of available provitamins A, other carotenoids and tocopherols than hay due to higher losses of these compounds during forage field-drying and hay storage. Ensiled grasses and legume forages contain higher levels of carotenoids and tocopherols than maize silage. Numerous terpenes are carried-over to milk and cheeses from grazed multifloral pastures or from hay, while silages are a poorer source of these flavour-affecting compounds. Data on alcohols, acids, esters, aldehydes and ketones in silage and especially information on their carry-over to milk are insufficient. Milk can gain a bad smell from a stable atmosphere if silage, particularly of poor quality, is fed. Red clover silage feeding can cause considerable levels of estrogenic equol in milk. Deoxynivalenol and zearalenone are the main mycotoxins formed in silage. Their content is reduced by the activity of both some lactic acid bacteria in silage and rumen microflora. The excretion of the mycotoxins in milk is generally low. Silages can be a pool of the undesirable bacteria Bacillus cereus, Clostridium tyrobutyricum and Listeria monocytogenes. Milk contamination with these bacteria can be decreased by the prevention of silage deacidification following air access, and by improving the dairy farm environment, cow hygiene and by sanitary milk harvesting.     

Study of natural mango juice spoilage and microbial contamination with Penicillium expansum by high resolution H NMR spectroscopy

High resolution ¹H NMR has been applied to monitor the changes in the composition of natural mango juice subjected to spoilage and to microbial contamination with Penicillium expansum. A vast number of compounds undergoing changes upon these processes have been identified and their variations followed throughout time (132 h). Besides the formation of typical fermentation products (e.g. acetate, lactic acid, acetoin and isopropanol/2,3-butanediol) and the utilization of the major sugars (sucrose, glucose and fructose), there were changes in organic acids (e.g. decreases of quinic and shikimic acids with formation of 3,4,5-trihydroxycyclohexane acid in spoiled juice, and decreases of citric and malic acids in contaminated juice), amino acids (decreases of alanine, leucine, isoleucine and valine), and less abundant components such as oligosaccharides and aromatic compounds. The possibility of using these changes as early indicators of natural spoilage or P. expansum contamination is discussed.     

Comparison of methods in the recovery and amplificability of DNA from fresh and processed sardine and anchovy muscle tissues

An important condition for a successful PCR amplification is an efficient DNA-extraction procedure out of a complex biological matrix such as canned fish. In this study we compared six extraction methods, including commercial kit, in terms of DNA yield, purity and time requirement. Such methods were applied to distinguish small pelagic fish species (Sardina pilchardus and Engraulisencrasicolus) among commercial canned products. The quantity and quality of DNA extracted were evaluated using the ratio A₂₆₀/A₂₈₀. Data were submitted to principal component analysis (PCA) in order to assess the differences between PCR results of fresh and processed anchovy and sardine muscles. Two main PC characterised the PCR of sardine and anchovy (70% and 69% of all variance): principal component 1 (PC1) (4% and 60%) and principal component 2 PC2 (66.0% and 9%) for sardine and anchovy, respectively. According to the PC1, the PCI/SDS and Chelex extractions (in decreasing order) were positively correlated with results of PCR for both species.     

The members of the Bacillus cereus group are commonly present contaminants of fresh and heat-treated milk

To determine the level of milk contamination by Bacillus cereus sensu lato, 44 samples were collected from a dairy farm and two independent dairies in northeastern Poland. A total of 680 B. cereus sensu lato isolates were recovered. Based on spore counts, their highest level in milk was found during the spring and summer months. Although significant variations in chromosomal DNA polymorphisms among B. cereus sensu lato isolates were noted based on repetitive element sequence polymorphism (rep-PCR) and pulse-field gel electrophoresis (PFGE), indistinguishable B. cereus isolates were observed in all sampling points and locations. Both B. cereus sensu stricto/Bacillus weihenstephanensis and Bacillus thuringiensis cultured from milk harbored nheA, hblA, and cytK in, respectively, 80%, 55%, and 60% of the isolates. With respect to Bacillus mycoides/Bacillus pseudomycoides, 30% and 70% of theses isolates harbored, respectively, nheA and hblA. The presence of cytK was not detected in any isolate. Our data show the occurrence of potentially toxic B. cereus s.l. in both raw and heat-treated milk, thus emphasizing the requirement for precautions that prevent spore germination and vegetative proliferation by keeping the milk at low temperatures during all steps of production and dispensation to the consumers.     

Volatile compounds of leaves and fruits of Mangifera indica var. coquinho (Anacardiaceae) obtained using solid phase microextraction and hydrodistillation

Volatile compounds present on fruits and leaves of Mangifera indica var. coquinho were investigated by headspace solid phase microextraction (HS-SPME) and hydrodistillation (HD). Conventional techniques, such as hydrodistillation, may impart chemical changes to the original oil composition being also time-consuming. On the other hand, HS-SPME provides solvent-less extractions, shorter extraction times and may supply complementary information about the composition of the compounds. The HS-SPME technique was previously evaluated by the comparative study among the fibres: commercial PDMS, NiTi-ZrO₂ and NiTi-ZrO₂-PDMS. The fibre NiTi-ZrO₂-PDMS showed better sensitivity and precision and was used on the extraction of components. The influence of several parameters like the time and temperature of extraction and desorption time were examined to obtain better efficiency. Fruits and leaves were analysed in mature and immature stages. The profiles corresponding to the volatile compounds detected by both techniques are discussed.     

Evaluation of lactic acid bacteria and yeast diversity in traditional white pickled and fresh soft cheeses from the mountain regions of Serbia and lowland regions of Croatia

The goal of this study was the characterisation of indigenous lactic acid bacteria (LAB) and yeasts isolated from nine white pickled (BG) and nine fresh soft (ZG) artisanal cheeses collected in Serbia and Croatia. While LAB were present in all of the cheeses collected, yeasts were found in all BG cheeses but only in three ZG cheese samples. High LAB and yeast species diversity was determined (average H′_L = 0.4 and H′_Y = 0.8, respectively). The predominant LAB species in white pickled (BG) cheeses were Lactococcus lactis, Lactobacillus plantarum, and Leuconostoc mesenteroides, while in fresh soft (ZG) cheeses the most dominant LAB species were L. lactis, Enterococcus faecalis, and Leuconostoc pseudomesenteroides. Among the 20 yeast species found, Debaryomyces hansenii, Candida zeylanoides, and Torulaspora delbrueckii were found to be predominant in BG cheeses, while Yarrowia lipolytica was predominant in ZG cheeses. The characterisation of metabolic and technological potentials revealed that 53.4% of LAB isolates produced antimicrobial compounds, 44.3% of LAB strains showed proteolytic activity, while most of the yeast species possessed either lipolytic or proteolytic activity. In conclusion, the results obtained in this study showed that the composition of LAB and yeast populations in white pickled and fresh soft cheeses is region specific. The knowledge gained in this study could eventually be used to select region specific LAB and yeast strains for the production of white pickled and fresh soft artisanal cheeses with geographically specific origins under controlled conditions.     

Utilization of mango peels as a source of pectin and polyphenolics

Two different options for the combined recovery of pectin and phenolic compounds from mango peels, a byproduct of industrial mango processing, were developed. After extraction of dried mango peels with diluted sulfuric acid, the phenolic compounds were adsorbed using a styrene–divinylbenzene copolymerisate resin, and pectin was obtained from the effluent by precipitation with ethanol. Phenolic compounds were recovered from the resin with methanol and the eluate was lyophilized (Process I). Alternatively, the pectin was precipitated by adding the crude extract to ethanol. After removal of the organic solvent, the phenolic compounds were obtained from the aqueous phase of the precipitation bath using the adsorbent resin as described before (Process II). While in total, 129.4 mg/g polyphenols were detected in the lyophilizate obtained from Process I, only 71.0 mg/g dm could be recoverd from Process II. The profiles of the polyphenols were almost identical, revealing that during pectin precipitation preferential adsorption of polyphenolic compounds to the pectin may be excluded. Besides the characterization of the pectins and the phenolic compounds, investigations into the influence of the drying temperature on the polyphenolic content of the peels were carried out, indicating a significant loss of flavonol glycosides depending on heat exposure. On the other hand, some xanthone glycosides were formed during the drying process. Furthermore, antioxidative capacities of the lyophilized eluates were investigated using the DPPH, TEAC and FRAP assays. The antioxidative capacity of the extracts exceeded that of mangiferin and quercetin 3-O-glucoside, respectively, thus demonstrating mango peels to be a suitable source of health-beneficial compounds. The lyophilizates obtained from Process I showed higher antioxidative capacities in all three assays. These findings indicate a correlation between the amount of phenolic compounds and the antioxidative capacity.

Industrial relevance

Byproducts of mango processing amount to 35–60% of the total fruit weight. Their complete exploitation for further product recovery is a promising measure from both an environmental and economic point of view. In our previous study mango peels were found to be a rich source of pectin, with a high degree of esterification and phenolic compounds, like flavonol O- and xanthone C-glycosides. Therefore, two alternative processes for the combined recovery of pectin and polyphenols, which can easily be integrated in an existing pectin production process, were developed in the present study.     

The effect of chilled conditioning at 4 °C on selected water and lipid-soluble flavor precursors in Bison bison longissimus dorsi muscle and their impact on sensory characteristics

Water and lipid-soluble flavor precursors were monitored using chromatography methods in the longissimus dorsi (LD) muscle of six grain-fed Bison bison, stored at 4 °C for 2, 4, 8, 15 and 21 days in order to investigate their potential impact on sensory attributes of cooked bison meat. While pH and lipid-soluble compounds remained mostly unchanged, several changes in water-soluble compounds were observed. The breakdown of inosine-5′-monophosphate (IMP) led to increases in inosine, hypoxanthine and ribose (7-fold). Non-polar amino acids including valine, leucine and phenylalanine showed the most significant increases over 21 days. Trained panelists (n = 8) found a significant increase at day 15 in vinegary/sour aroma, tenderness and juiciness, while chewiness and connective tissue significantly decreased. Although, most flavor attributes were undetectable, partial least squares (PLS) analysis revealed most water-soluble precursors were positively correlated with extended conditioning as well as beef and oily/fatty flavors. Quantitative changes observed in flavor precursors may be responsible for some sensory attributes developed during the heating process.     

Microbiological quality of fresh lettuce from organic and conventional production

Previously there was no available information on the levels of indicator bacteria and the prevalence of pathogens in fresh lettuce grown in organic and conventional farms in Spain. A total of 72 lettuce samples (18 farms for 4 repetitions each) for each type of the agriculture were examined in order to assess the bacteriological quality of the lettuces, in particular the prevalence of selected pathogens. The lettuce samples were analyzed for the presence of aerobic mesophilic, psychrotrophic microorganisms, yeasts and moulds, Enterobacteriaceae, mesophilic lactic acid bacteria, Pseudomonas spp. and presumptive Escherichia coli, Salmonella spp. and Listeria monocytogenes. The mean aerobic mesophilic counts (AM) were 6.35 ± 0.69 log₁₀ cfu g⁻¹ and 5.67 ± 0.80 log₁₀ cfu g⁻¹ from organic and conventional lettuce, respectively. The mean counts of psychrotrophic microorganisms were 5.82 ± 1.01 log₁₀ cfu g⁻¹ and 5.41 ± 0.92 log₁₀ cfu g⁻¹ from organic and conventional lettuce, respectively. Yeasts and moulds (YM) mean counts were 4.74 ± 0.83 log₁₀ cfu g⁻¹ and 4.21 ± 0.96 log₁₀ cfu g⁻¹ from organic and conventional lettuce, respectively. Lactic acid bacteria (LAB) were present in low numbers and the mean counts were 2.41 ± 1.10 log₁₀ cfu g⁻¹ and 1.99 ± 0.91 log₁₀ cfu g⁻¹ from organic and conventional lettuce, respectively. Pseudomonas spp. mean counts were 5.49 ± 1.37 log₁₀ cfu g⁻¹ and 4.98 ± 1.26 log₁₀ cfu g⁻¹ in organic and conventional lettuce, respectively. The mean counts for Enterobacteriaceae were 5.16 ± 1.01 log₁₀ cfu g⁻¹ and 3.80 ± 1.53 log₁₀ cfu g⁻¹ in organic and conventional lettuce, respectively. E. coli was detected in 22.2% (16 samples) of organic lettuce and in 12.5% (9 samples) of conventional lettuce. None of the lettuce samples was positive for E. coli O157:H7, L. monocytogenes and Salmonella spp. From the samples analyzed by principal component analysis (PCA) a pattern with two different groups (conventional and organic) can be observed, being the highest difference between both kinds of samples the Enterobacteriaceae count.     

Regulation of lipid and glucose homeostasis by mango tree leaf extract is mediated by AMPK and PI3K/AKT signaling pathways

Ethanolic extract of Mangifera indica (mango) dose-dependently decreased serum glucose and triglyceride in KK-A^y mice. Our in vitro and in vivo investigations revealed that the effect of mango leave extract (ME) on glucose and lipid homeostasis is mediated, at least in part, through the PI3 K/AKT and AMPK signaling pathway. ME up-regulated the expression of PI3 K, AKT and GYS genes by 2.0-fold, 3.2-fold, and 2.7-fold, respectively, leading to a decrease in glucose level. On the other hand, ME up-regulated AMPK and altered lipid metabolism. ME also down-regulated ACC (2.8-fold), HSL (1.6-fold), FAS (1.8-fold) and PPAR-γ (4.0-fold). Finally, we determined that active metabolites of benzophenone C-glucosides, Iriflophenone 3-C-β-glucoside and Foliamangiferoside A from ME, may play a dominant role in this integrated regulation of sugar and lipid homeostasis.     

Influence of apple purée preparation and storage on polyphenol contents and antioxidant activity

The polyphenolic components of Idared and Shampion apple purées were determined by HPLC; chlorogenic acid was the most abundant acid (20.0 mg/100 g in microwaved Idared); other polyphenols identified in high concentrations included (−)-epicatechin, procyanidin B1 and B2; quercetin and cyanidin glycosides were found in minor concentrations. The Shampion purées had higher total phenolics (142 mg/100 g) and procyanidin B2 concentrations (17.3 mg/100 g) than the Idared ones, and polymeric procyanidins represented 41% of all polyphenols. Antioxidant capacities of the samples, determined by spectrophotometric methods and EPR spectroscopy, correlated well with the concentration of polyphenols. The antioxidant properties could be better represented by EPR than by UV–vis measurements. The latter require transparent (clear) samples whereas EPR can be a method of choice in the assessment of radical-scavenging activity of dense and cloudy apple purées. Our results support the putative high antioxidant value of apple purées and define their capacity in terms of the major constituents. Apple purées are a rich source of natural antioxidants, especially of chlorogenic acid and procyanidins.     

The effect of sugar concentration and starter culture on instrumental and sensory textural properties of chorizo-Spanish dry-cured sausage

In this study, instrumental and sensory textural properties of chorizo with different levels of glucose (0.1%, 0.5% and 1.0%) and with different starter cultures (Lactobacillus sakei K29, Pediococcus sp. P22 and Pediococcus sp. P208) were studied as well as the relationship between them. The ripening process was followed by physico-chemical and microbiological analysis. Starter culture and concentration of glucose had a highly significant effect on pH, moreover an interactive effect of both factors was found; and also of day of ripening and both starter culture and concentration of glucose. In general terms, changes of pH over time are influenced by the presence of sugar and starter culture even if all chorizos showed at first a rapid decrease, a stay or slow decrease, and a final rise. Texture profile analysis (TPA) proved that hardness and chewiness differ significantly among chorizos with or without starter cultures, except in the batch with 0.1% sugar. Furthermore, the highest values in both textural parameters were found in batches with 0.5% and 1% sugar. The texture differences between chorizos just described were also noticeable in the sensorial evaluation. Likewise, instrumental textural attributes showed significant correlations with sensorial analysis.