Manuel Jarén-Galán

Lipoxygenase activity during pepper ripening and processing of paprika

Abstract The crude enzymatic extract obtained directly by trituration of the fruits of Capsicum annuum in phosphate buffer followed by filtration was shown to be suitable for the measurement of lipoxygenase activity. The use of Triton X-100 did not improve extraction and the use of DTT to protect the enzyme against oxidizers was not necessary. The optimum pH was 7 for the extraction and 6.5 for measurement of activity. The number of previous harvests from the plant had a marked effect on the levels of lipoxygenase activity during ripening of the fruits from two varieties of pepper. During drying, there was a progressive loss of activity in both varieties.

Decoloration of vegetable oils and oleoresins with recovery of unaltered pigments

The present study confirms that N,N-dimethylformamide for the extraction of chloroplast pigments from vegetable tissues shows no differences from the usual acetone or methanol. Therefore, it can be applied to fats, as it allows separation of lipids and pigments by means of phase distribution between light petroleum ether and N,N-dimethylformamide. The ether phase retains the decolored fatty matter, and the pigments dissolved in N,N-dimethylformamide can be recovered totally unaltered.This method has been applied to oleoresins and oils from different products and origins. Satisfactory results have been obtained in terms of the degree of decoloration and the percentage of oil recovered. At the same time, the unaltered pigment concentrate obtained from the hypophase could be used as a color enhancer in the chemico-pharmaceutical industry.

Differences in the Activity of Superoxide Dismutase, Polyphenol Oxidase and Cu-Zn Content in the Fruits of Gordal and Manzanilla Olive Varieties

Activity of the enzymes superoxide dismutase (SOD) and polyphenol oxidase (PPO) as well as Cu-Zn content have been monitored during the thirteen weeks growth of both Gordal and Manzanilla olive variety fruits. These metalloenzymes, with Cu and Zn in the prostetic group, are involved in controlling the redox balance in the chloroplast environment. The results indicated that, under similar phenological and environmental conditions, there are periodic peaks of SOD activity in both varieties, followed by fluctuations in the copper content of the fruit. This was interpreted as a common and simultaneous response to situations of oxidative stress, and this response was more intense in the variety Gordal. The enzyme PPO showed an activity peak at start of growth and then practically disappeared. Thus, its activity cannot be correlated with situations of stress or with changes of Cu and Zn in the fruit.

Picrocrocin kinetics in aqueous saffron spice extracts (Crocus sativus L.) upon thermal treatment

The kinetics of picrocrocin degradation in aqueous extracts of saffron upon thermal treatment from 5 to 70 °C have been studied, together with the degradation of purified picrocrocin in water at 100 °C. The best fits to experimental data were found for a second-order kinetics model. Picrocrocin showed high stability with half-life periods (t(1/2)) ranging from >3400 h at 5 °C in saffron extracts to 9 h in the experiments with purified picrocrocin at 100 °C. In saffron extracts, the evolution of the rate constant (k) with temperature showed maximum values at 35 °C, and filtration of the extracts contributed to picrocrocin stability. In the case of purified picrocrocin, the generation of safranal in the first 5 h (yield up to 7.4%) was confirmed. Spectrometric parameters used in saffron quality control (E(1cm)(1%) 257 nm and ΔΕ(pic)) were not appropriate for documenting the evolution of picrocrocin.

Xanthophyll esters are found in human colostrum

SCOPE Carotenoids in human milk are associated with other lipid counterparts in several metabolic processes. One interesting association that has not been demonstrated to date is the presence of xanthophyll esters. Colostrum and mature milk samples were analyzed to determine the occurrence of xanthophyll esters and identify the compounds. Thus, the association of the amounts of these compounds with lactation and whether they are significant contributors to the carotenoid profile of human milk was assessed. METHODS AND RESULTS Pre-term and term delivering mothers were included in the study to donate colostrum at 3-5 days postpartum and mature milk at 15 days postpartum. Carotenoids extracts were subjected to a clean-up procedure to remove the triacylglycerol fraction and then analyzed by HPLC-MSn . Identification of xanthophyll esters was achieved by considering their chromatographic behaviour, UV-visible characteristics and MSn features. CONCLUSION Xanthophyll esters are significant contributors to the carotenoid profile in the colostrum, while mature milk does not contain these compounds. Therefore, fatty acid acylation to xanthophylls is activated during the accumulation of carotenoids in the human mammary gland. The sharp decline in the amount of xanthophyll esters in mature milk indicates that the lipophilic components are those recently incorporated in the mammary epithelium.

Pigments in the algal biomass from aerobic waste water depuration ponds

A study of the algal pigments of the biomass from aerobic treatment ponds was made with the aim of supporting other procedures to identify the predominant species that grow in the experimental condition assayed. Chlorophillic and carotenoids pigments were separated and purified by TLC for later identification and quantification by HPLC. A significant predominance of fucoxanthin and diadinoxanthin which are specific of Diatoms were found, as well as very low proportions of other non-specific pigments from other minor growing species. The absence of chlorophyll ‘b’ and a low level of ‘c’ owing to a possible coexistence of Diatom and Cyanophyceae in the culture, must be emphasized.In the experimental conditions assayed the addition of silicates to the waste water promotes the growth of Diatoms specifically Fragilaria pinnata, and also induces the formation of a secondary microflora of Cyanophyceae type with bentonic characteristics, mainly Phormidium fragile, the principal characteristics of which, are a ready tendency to sedimentation and a large size, facilitating their separation by filtration or decantation.

Activities, bioavailability, and metabolism of lipids from structural membranes and oils: promising research on mild cognitive impairment

Graphical abstract Figure. No caption available. &NA; Concomitant with increased lifespan, large segments of the population are experiencing cognitive decline, which might progress to Alzheimers disease (AD). Currently, there is no cure for AD and, once the neurodegenerative disorders are established, patients use pharmacologic therapy to slow the progression of the symptoms and require appropriate care to manage their condition. The preclinical stage of neural degeneration that progress through mild cognitive impairment (MCI) before the onset of AD is when it might be possible to introduce behavioral changes and pharma‐nutritional interventions that modify the risk factors of MCI conversion to AD. Some food components accumulate in brain tissues, where they play essential roles. Among them, polar lipids, omega 3 fatty acids, and carotenoids appear to work additively or synergistically. Therefore, there is an opportunity to formulate nutraceuticals/functional foods to slow the progression of MCI. In this paper, we review the biochemical bases and recent interventions with bioactive lipids‐rich formulations. Based on accumulated evidence, we propose that appropriate large‐scale trials are warranted.