Franco Maria Lajolo

FT-IR spectroscopy as a tool for measuring degree of methyl esterification in pectins isolated from ripening papaya fruit

A straightforward method using Fourier transform-infrared (FT-IR) spectroscopy for determination of methyl esterification degree (MED) of pectins is described. The method was used for measuring methylation level of different pectin fractions isolated from papaya (Carica papaya) fruit in three ripening stages as well as of the bulk pectin without isolation from the cell wall. All the samples used were in solid state. MED values were calculated from absorbance spectra of the samples, using a relationship involving absorbance intensities for 1630 and 1745 cm−1 bands. Under present experimental conditions these bands could be assigned to the stretching frequencies for the carbonyl groups of galacturonic acid and its methyl ester, respectively. The sample quantities required for the technique were less than 1 mg and the results obtained were in agreement with those achieved using an established method.

Avaliação da atividade antioxidante utilizando sistema beta-caroteno/ácido linoléico e método de seqüestro de radicais DPPH

SUMMARY EVALUATION OF THE ANTIOxIDANT ACTIVITy USING THE B-CAROTENE/LINOLEIC ACID SySTEM AND THE DPPH SCAVENGING METHOD. The antioxidant activity of fruit extracts (acerola, acai, black-berry and strawberry) and pure compounds has been analysed by two methods: β-carotene/linoleic acid and DPPH•(2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay. First, those methodologies were adapted to be performed in microplates, in order to reduce the sample and reagent amounts, to increase the number of simultaneous analyses and to automate absorbance lectures. The results showed that the antioxidant activity of the fruit extracts was in accordance with those of pure ascorbic acid and phenolic compounds, in the two systems. The acerola extract, due to its high vitamin C content, acted as pro-oxidant, but acai, black-berry and strawberry extracts acted as antioxidants in β-carotene/

Physico-chemical changes related to quality of five strawberry fruit cultivars during cool-storage

Abstract Several parameters related to strawberry quality, such as texture, anthocyanin content, titratable acidity, pH, total ascorbic acid, and total soluble sugars, were evaluated over a week of cool storage. The results indicated that low temperature used to increase strawberry shelf-life could also induce small changes in some of the quality parameters studied. However, the data revealed the importance of the cultivar in question since there were some contrasting responses among the cultivars. Also the initial values for some of the parameters were clearly different, indicating that the cultivar is the most important factor for determining post-harvest quality and extended shelf-life. Texture is an important parameter with regard to shelf-life but was not determined since the ‘Mazi’ cultivar had a high initial value for texture but no changes occurred over the storage period. However, it had the shortest shelf-life. Changes in anthocyanin content were highly dependent on the cultivar. Except for ‘Toyonoka,’ no marked changes were observed in titratable acids or pH. Ascorbic acid decreased by 50% in all cultivars. The profiles of soluble sugars were different among cultivars but, for all of them, sucrose disappeared on day 2 of storage.

Chemical Composition and Antioxidant/Antidiabetic Potential of Brazilian Native Fruits and Commercial Frozen Pulps

Foods provide essential and bioactive compounds with health-promoting properties such as antioxidant, anti-inflammatory, and hypocholesterolemic activities, which have been related to vitamins A, C, and E and phenolic compounds such as flavonoids. Therefore, the aim of this work was to identify potential sources of bioactive compounds through the determination of flavonoids and ellagic acid contents and the in vitro antioxidant capacity and alpha-glucosidase and alpha-amylase inhibitory activities of Brazilian native fruits and commercial frozen pulps. Camu-camu, cambuci, uxi, and tucuma and commercial frozen pulps of cambuci, cagaita, coquinho azedo, and araca presented the highest antioxidant capacities. Cambuci and cagaita exhibited the highest alpha-glucosidase and alpha-amylase inhibitory activities. Quercetin and kaempferol derivatives were the main flavonoids present in most of the samples. Ellagic acid was detected only in umbu, camu-camu, cagaita, araca, and cambuci. According to the results, native Brazilian fruits can be considered as excellent sources of bioactive compounds.

Bioactive Compounds and Antioxidant Capacity of Exotic Fruits and Commercial Frozen Pulps from Brazil

The objective of this work was to characterize exotic fruits (cambuci, araça-boi, camu-camu, jaracatia, araça) and commercial frozen pulps (araça, cambuci, umbu, coquinho, pana, native passion fruit, cagaita) from Brazil in relation to their bioactive compounds contents and antioxidant capacity. Camu-camu (Myrciaria dubia) presented the highest vitamin C and total phenolics contents (397 and 1797 mg/100 gf.w., respectively) and the highest DPPH• scavenging capacity. Coquinho (Butia capitata) also showed a significant vitamin C content (43 mg/100 gf.w.). Among the commercial frozen pulps, cagaita presented the higher DPPH scavenging activity and inhibition of β-carotene bleaching. A good correlation between total phenols and DPPH scavenging activity was found for fruits (r = 0.997) and commercial frozen pulps (r = 0.738). However, no correlation was found for total phenols and inhibition of β-carotene bleaching. Quercetin and kaempferol derivatives were the main flavonoids present in all samples and cyanidin derivatives were detected only in camu-camu. Camu-camu and araça (Psidium guineensis) showed the highest total ellagic acid contents (48 and 63.5 mg/100 gf.w.). All commercial frozen pulps presented lower contents of bioactive compounds and antioxidant capacity than their respective fruits. According to our results, camu-camu and araça might be sources of bioactive compounds.

Composition and Functional Properties of Banana Flour from Different Varieties

The chemical composition and some physico-chemical characteristics of the flour obtained from eight different banana varieties are presented. The flour was prepared by freeze-drying a homogenate of green banana pulp. Amylose, starch, dietary fiber, protein, ash, moisture and lipid contents were determined. Viscosity and gelatinization of starch were also investigated. Banana flour is rich in starch granules. Peak temperature of gelatinization varied from 68 to 76 °C according to the variety. All of them showed an increase in viscosity during cooling but the variety Ouro colatina showed more stability during shearing and cooling. Chemical composition of the flour also varied according to the variety. The range obtained were 61—76.5% starch, 19—23% amylose, 2.5—3.3% protein, 4—6% moisture, 0.3—0.8% lipids, 2.6—3.5% ashes, and 6—15.5% total fiber. Considering that the flour production is easier and faster than the isolation of the starch, it would be not only more practical but also less expensive to use the flour instead.

Functionality of Bioactive Compounds in Brazilian Strawberry (Fragaria × ananassa Duch.) Cultivars: Evaluation of Hyperglycemia and Hypertension Potential Using in Vitro Models

Fruits of seven fully ripened strawberry cultivars grown in Brazil (Dover, Camp Dover, Camarosa, Sweet Charlie, Toyonoka, Oso Grande, and Piedade) were evaluated for total phenolics, antioxidant activity based on DPPH radical scavenging assay, and functionality such as inhibition of alpha-amylase, alpha-glucosidase, and angiotensin I-converting enzyme (ACE) relevant for potentially managing hyperglycemia and hypertension. The total phenolics content ranged from 966 to 1571 microg of gallic acid/g of fruit fresh weight for Toyonoka and Dover, respectively. No correlation was found between total phenolics and antioxidant activity. The major phenolic compounds in aqueous extracts of strawberries were ellagic acid, quercetin, and chlorogenic acid. Strawberries had high alpha-glucosidase inhibitory activity. However, alpha-amylase inhibitory activity was very low in all cultivars. This suggested that strawberries could be considered as a potential dietary source with anti-hyperglycemic potential. The evaluated cultivars had no significant ACE inhibitory activity, reflecting low anti-hypertensive potential.

Consumo de suplementos por alunos de academias de ginástica em São Paulo

The increase in the number of fitness centers in the city of Sao Paulo, together with the increase in the offering of different supplements, has raised interest in the study of the consumption of supplements among fitness center users. The consumption of supplements by the general public has not been well quantified yet, and little information has been published about this subject. The arrival of new supplements in the market place has been faster than the creation of regulations and the accomplishment of researches proving their effects and determining the safety for their long-term use. In a sample of 309 users from seven fitness centers in Sao Paulo in 1999, 74 (23.9%) used at least one type of supplement, 77,0% of whom were male and 23,0% were female. The most consumed supplements were amino acids or other proteic products (38.9%), and the daily intake was the most mentioned consumption frequency (90.3%). The correlation between money expenditure with supplement and individual income was 27.5% (p = 0.0483; n = 52), and the expenses were greater among men; the correlation with family income was 36.1% (p = 0.0137; n = 46) and with Body Mass Index it was to 17.1% (p = 0.1564; n = 70). The conclusion was that the consumption of supplements is significant in the evaluated group, showing the need for more studies about the consumption of these products and their effects, focusing on nutrition education approaches in order to increase the level of information about them and to guarantee the safety of their use.

Effect of Different Cooking Conditions on Phenolic Compounds and Antioxidant Capacity of Some Selected Brazilian Bean (Phaseolus vulgaris L.) Cultivars

The effects of different cooking conditions such as soaking, atmospheric (100 degrees C) or pressure boiling (121 degrees C), and draining of cooking water following thermal treatment on phenolic compounds and the DPPH radical scavenging capacity from two selected Brazilian bean cultivars (black and yellow-brown seed coat color) were investigated using a factorial design (2(3)). Factors that significantly reduced the total phenolic contents and antioxidant capacity in both cultivars were the soaking and draining stage. Independent of cooking temperature, total phenolics and antioxidant capacities were enhanced in treatments without soaking and where cooking water was not discarded, and this was likely linked to an increase of specific phenolic compounds detected by high performance liquid chromatography such as flavonols and free phenolic acids in both cultivars. Cooking of beans either at 100 or 121 degrees C, without a soaking stage and keeping the cooking water, would be recommendable for retaining antioxidant phenolic compounds.

Absorption and metabolism of cyanidin-3-glucoside and cyanidin-3-rutinoside extracted from wild mulberry (Morus nigra L.) in rats

The mechanism of uptake of anthocyanins (as well as the type) from food in the intestine is not clear. Anthocyanin-rich extract from wild mulberry, composed of cyanidin-3-glucoside (79%) and cyanidin-3-rutinoside (cy-3-rut) (19%), was orally administered to Wistar rats, and their concentrations were determined in plasma, kidney, and the gastrointestinal (GI) tract. The 2 glycosylated forms showed maximum concentration at 15 minutes after oral administration, both in plasma and kidney. The cyanidin-3-glucoside and cy-3-rut were found in plasma as glucuronides, as sulfates of cyanidin, and as unchanged forms. The area under the curve of concentration vs time (AUC(0-8h)) was 2.76 +/- 0.88 microg hour/mL and 9.74 +/- 0.75 microg hour/g for plasma and kidney, respectively. In spite of the low absorption, the increase in plasma anthocyanin level resulted in a significant increase in antioxidant capacity (P < .05). In the GI tract (stomach and small and large intestines), cyanidin glycosides were found unchanged, but a low amount of the aglycone form was present. Anthocyanin glycosides were no longer detected in the GI tract after 8 hours of administration. In vitro fermentation showed that the 2 cyanidin glycosides were totally metabolized by the rat colonic microflora, explaining their disappearance. In addition, the 2 products of their degradation, cyanidin and protocatechuic acid, were not detected in plasma and probably do not influence plasma antioxidant capacity. As found by the everted sac model, anthocyanins were transported across the enterocyte by the sodium-dependent glucose transporter.