Volatile components of avocado leaves (Persea americana mill) from the Mexican race

The chemical composition of the volatile oil of avocado leaves from Mexican race (Persea americana Mill) grown in the highlands of Mexico was investigated by gas chromatography and gas chromatography-mass spectrometry. Thirty compounds were identified accounting for 92.45% of the oil. Estragol (78.12%), α-cubebene (3.58%), methyl eugenol (3.37%) and β-caryophyllene (2.10%) were the major components representing more than 87%. The oil has a characteristic aroma similar to anise-tobacco.     

Partial purification and enzymatic characterization of avocado (Persea americana Mill,cv. Hass) lipoxygenase

Detrimental effects on minimally processed fruits and vegetables induced by increased lipoxygenase (LOX) activity are a major concern in the food industry. Partial purification and enzymatic characterization of lipoxygenase (LOX) from avocado fruit (Persea americana Mill, cv. Hass) is presented. Avocado LOX was partially purified by fractional precipitation with ammonium sulfate, followed by anion exchange adsorption. Substrate specificity and effects of temperature, pH and calcium ion concentration on LOX activity were determined. Likewise, the in vitro ability of avocado LOX to co-oxidize β-carotene was determined. LOX showed a higher substrate affinity for linolenic than for linoleic acid. Optimum activity was reached at 40 °C, pH 6.5, and 0.20 mM of calcium ion concentration. Avocado LOX showed β-carotene co-oxidation capability. Considering the optimums and operational ranges established for each studied factor, strategies concerning the inactivation of LOX may be proposed to reduce the detrimental effects on minimally processed avocado products. Additionally, the co-oxidation capability of avocado LOX may be of interest for the avocado industry due to its potential application as a bleaching agent.     

Palynological,physico‐chemical and organoleptic characteristics of carob tree (Ceratonia siliqua L.) honey from Sicily

This study shows the results of melissopalynological and sensory evaluations on twenty‐five carob tree honey samples coming from Sicily and declared unifloral by the local beekeepers. This specific carob tree honey production is erratic and limited because of its cold weather spreading, depending on seasonal trends that influence both the final amount and quality of honey itself. According to the melissopalynological results on samples, a minimum of 15% carob tree pollen was considered sufficient to typify these honeys as unifloral. The physico‐chemical analysis was performed on the samples satisfying this percentage and determined the following parameters: moisture, pH, acidity, HMF, diastase activity, electrical conductivity, ash, sugar and colour. Physico‐chemical analyses showed medium to high values for diastase activity, electrical conductivity, free acidity and moisture.     

Antioxidant properties and phenolic content of sulla (Hedysarum spp.) honeys from Southern Italy

The geographical origin greatly influences the qualitative and nutraceutical characteristics of honey. In this study, a total of twenty‐four sulla honeys from eight different geographical areas of Southern Italy have been examined for total phenolic content (Folin–Ciocalteu method), antioxidant activity (FRAP and DPPH assays), colour intensity (ABS₄₅₀), and identification and quantification of phenolic acids (RP‐HPLC/UV‐VIS method). The total phenolic content ranged from 47.9 (Potentino honeys) to 248.3 mg GAE per kg honey (Penisola Sorrentina honeys). The antioxidant activity ranged from 47.06% (Basso Pollino honeys) to 88.25% (Penisola Sorrentina honeys), and from 98.26 μM Fe (II) (Potentino honeys) to 786.53 μm Fe (II) (Tarantino honeys) for DPPH and FRAP assays, respectively. Major phenolic acids identified in analysed samples were gallic, caffeic and ferulic acids. Correlations between the parameters analysed were statistically significant (P < 0.05). The results of the study showed that the parameters studied are greatly affected by the peculiarities of their production area.     

Physical properties,chemical characterization and fatty acid composition of Mexican chia (Salvia hispanica L.) seeds

Chia seeds were utilized by Aztecs as food and for medicinal purposes. Nowadays, this crop is gaining importance in many countries, due to its nutritional attributes. Some physical properties and chemical characteristics of chia seeds from four different regions of Mexico were evaluated and compared. Seed size distribution was not significantly affected (P > 0.05) by the region, with similar values of seed length (2.03–2.10 mm), width (1.27–1.32 mm), thickness (0.77–0.81 mm) and surface area (4.95–5.42 mm²). Bulk density (662–741 kg m^?3), geometry and granulometric distribution were also determined. Origin of tested seeds significantly (P < 0.05) influenced their composition; all seeds had high contents of protein (18.5–22.3%), fat (21.5–32.7%) and fibre (20.1–36.1%). Chia seeds ratio between omega‐3 and omega‐6 fatty acids was 3:1 for the studied regions; seeds from Chiapas and Michoacán had the highest proportion of ω‐6 and ω‐3 fatty acids. The studied seeds contained phenolic compounds in the range of 0.53–0.71 mg GAE g^?1.     

Cagaita (Eugenia dysenterica DC.) of the Cerrado of Minas Gerais, Brazil: Physical and chemical characterization, carotenoids and vitamins

The physical characteristics (diameters, height and mass), chemical composition (tritratable acidity, soluble solids, pH, moisture, ash, protein, lipids and total dietary fiber), occurrence and content of vitamin C (ascorbic acid and dehydroascorbic acid), carotenoids (??-carotene, ??-carotene, ??-cryptoxanthin and lycopene), vitamin E (??-, ??-, ??- and ??-tocopherol and tocotrienol) and folates (tetrahydrofolate, 5-methyltetrahydrofolate and 5-formyltetrahydrofolate) were evaluated in the cagaita obtained from the Cerrado of Minas Gerais, Brazil. The analyses of vitamin C and carotenoids were performed by HPLC-DAD and vitamin E and folates by HPLC with fluorescence detection. The cagaita pulp presented high content of moisture (91.56 g 100 g^− 1), vitamin C (34.11 mg 100 g^− 1) and folates (25.74 ??g 100 g^− 1). The presence of protein (0.63 g 100 g^− 1), ash (0.18 g 100 g^− 1), lipids (0.57 g 100 g^− 1), carbohydrates (5.54 g 100 g^− 1), dietary fiber (1.54 g 100 g^− 1) and carotenoids (0.77 mg 100 g^− 1) was observed in its composition. Vitamin E isomers were not detected. Consumption of cagaita (100 g) contributed significantly to supply the daily requirements of vitamin C (on average 71.0%), vitamin A (on average 7.5%) and folates (on average 7.9%). The cagaita showed high pulp yield, reduced total energy value and was considered a source of vitamin C, which play important role in human health.