Anna Rizzolo

A single portion of blueberry (Vaccinium corymbosum L) improves protection against DNA damage but not vascular function in healthy male volunteers

It has been suggested that anthocyanin-rich foods may exert antioxidant effects and improve vascular function as demonstrated mainly in vitro and in the animal model. Blueberries are rich sources of anthocyanins and we hypothesized that their intake could improve cell protection against oxidative stress and affect endothelial function in humans. The aim of the study was to investigate the effect of one portion (300 g) of blueberries on selected markers of oxidative stress and antioxidant protection (endogenous and oxidatively induced DNA damage) and of vascular function (changes in peripheral arterial tone and plasma nitric oxide levels) in male subjects. In a randomized cross-over design, separated by a wash out period ten young volunteers received one portion of blueberries ground by blender or one portion of a control jelly. Before and after consumption (at 1, 2, and 24 hours), blood samples were collected and used to evaluate anthocyanin absorption (through mass spectrometry), endogenous and H(2)O(2)-induced DNA damage in blood mononuclear cells (through the comet assay), and plasma nitric oxide concentrations (through a fluorometric assay). Peripheral arterial function was assessed by means of Endo-PAT 2000. Blueberries significantly reduced (P < .01) H(2)O(2)-induced DNA damage (-18%) 1 hour after blueberry consumption compared to control. No significant differences were observed for endogenous DNA damage, peripheral arterial function and nitric oxide levels after blueberry intake. In conclusion, one portion of blueberries seems sufficient to improve cell antioxidant defense against DNA damage, but further studies are necessary to understand their role on vascular function.

Blanching improves anthocyanin absorption from highbush blueberry ( Vaccinium corymbosum L.) purée in healthy human volunteers: a pilot study.

Blueberries ( Vaccinium corymbosum L.) are rich sources of phenolics and anthocyanins (ACNs). We investigated the absorption of ACNs after consumption of one portion (300 g) of minimally processed blueberry purée (P) obtained from blanched (BL) or unblanched (NB) berries. A repeated-measures, crossover design study was conducted on healthy human volunteers. Blood was drawn between baseline and 24 h after BL-P or NB-P consumption, while urine were collected from the day before the experiment up to 48 h. Total plasma ACN content was not significantly different, while phenolics content was higher in BL-P with respect to NB-P. The maximum ACN absorption in plasma was observed after 1.5 h from the intake of the purées and was significantly higher (p ≤ 0.05) after the intake of BL-P. Both products increased the excretion of hippuric acid in urine. In conclusion, blanching had no significant effect on total ACN content and enhanced their absorption from minimally processed purées.

Modification of glass transition temperature through carbohydrates addition and anthocyanin and soluble phenol stability of frozen blueberry juices

Abstract To evaluate the influence of carbohydrate addition on anthocyanin and soluble phenol stability, blueberry juices were added with 20% (wt/wt) of maltose, sorbitol and a mixture (1:1) of glucose and fructose. A juice without addition of carbohydrates was used as a control. The juices were frozen and stored up to six months at −10, −20 and −30 °C. The transition temperatures T m ′ correlated with those of the added sugars. The glass transition was shifted to higher temperatures by addition of maltose and no significant changes in the transition temperatures were noticed with storage time. Anthocyanin and soluble phenol changes were mainly influenced by storage temperature and storage time: the lower the temperature, the shorter the storage time, the lower the changes. Sugar addition had no influence on anthocyanin content.

The influence of harvest date on the volatile composition of ‘Starkspur Golden’ apples

Abstract The effect of harvest date on the volatile composition of ‘Starkspur Golden’ apples ( Malus domestica Borkh.) was studied. The fruits were picked 158, 172 and 181 days after full bloom (DAFB). Volatile substances were sampled by dynamic headspace on intact fruits and analysed by capillary gas chromatography. Qualitative and quantitative differences were found among the harvest dates. Apples picked 172 DAFB showed the highest amount of volatiles, as well as the best volatile composition; they had a low content of high boiling-point esters and alcohols and a high content of low boiling-point esters, which are responsible for the characteristic ‘Golden’ aroma. Apples picked 158 and 181 DAFB showed a volatile substance composition typical of immature and overripe apples, respectively.

Influence of harvest date on ripening and volatile compounds in the scab-resistant apple cultivar ‘Golden Orange’

Summary The quality of scab-resistant apple cv. ‘Golden Orange’, as influenced by harvest time, was evaluated in comparison with the scab-susceptible cv. ‘Golden Delicious’ (clone B) (Golden B). Fruits from both cultivars were harvested on three different dates and ripened at 20°C. Quality parameters at harvest [fruit mass, flesh firmness, starch hydrolysis, soluble solids content (SSC), titratable acidity (TA)], colour, ethylene production (EP), development of headspace volatiles during post-harvest ripening, and sugar and organic acid compositions at the end of ripening were measured. At harvest, firmness, SSC, TA, starch hydrolysis and Streif Index indicated that ‘Golden Orange’ apples were less mature than ‘Golden B’ apples, even if their skin colour was more yellow. Generally, during post-harvest ripening, ‘Golden Orange’ apples showed lower EP, lower total volatile production, and their skin turned as yellow as ‘Golden B’. ‘Golden Orange’ apples differed from ‘Golden B’ in their sugar, organic acid and volatile compound compositions. These differences were independent of harvest date and could explain the different sensory descriptions peculiar to this cultivar. Compounds that contributed most to the characteristic aroma were ethyl 2-methylbutanoate and hexyl and 2-methylbutyl acetate in ‘Golden B’ apples, and ethyl and hexyl 2-methylbutanoate, ethyl hexanoate and hexyl acetate in ‘Golden Orange’ fruit, at all harvest times. The concentrations of these volatiles were largely dependent on harvest date and on the length of post-harvest ripening.

Optical properties-microstructure-texture relationships of dried apple slices: spatially resolved diffuse reflectance spectroscopy as a novel technique for analysis and process control

The potential of spatially resolved diffuse reflectance spectroscopy in the 500-1000 nm range by means of a fiber-optics probe was investigated for acquiring scattering and absorption properties of air dried apple rings subjected to different pre-treatment conditions: without osmo-dehydration (TQ) and with osmo-dehydration for 1 (OSMO1) and 3 hours (OSMO2). The fresh apple rings were produced from ‘Golden Delicious’ apples at harvest (H) and 5 month storage at 2 conditions: controlled atmosphere (CA) and normal atmosphere (NA). Microstructure properties of the dried apple rings were also obtained from X-ray micro-CT measurements. The TQ samples were found to have significantly higher scattering properties, thicker tissue, smaller pore sizes, were less crispy, and required higher snapping work or rupture energy than the OSMO1 and OSMO2 samples. On the other hand, no significant differences were observed between the scattering properties, microstructure, and textural quality of the OSMO1 and OSMO2 apple rings. From these results, it was concluded that there is a clear process-microstructure-quality relation in osmo-air-dried apples which can be measured non-destructively with spatially resolved diffuse reflectance spectroscopy. AC C EP TE D M AN U SC R IP T ACCEPTED MANUSCRIPT 2 Therefore, this study confirmed the potential of spatially resolved diffuse reflectance spectroscopy for non-destructive quality assessment of air-dried apple slices, which provides perspectives for drying process optimization.

Changes in some odour-active compounds in paclobutrazol-treated ‘Starkspur Golden’ apples at harvest and after cold storage

Abstract Apple trees ( Malus domestica Borkh. cv ‘Starkspur Golden’) were treated 25 days after full bloom (DAFB) with paclobutrazol (PBZ) as a soil-drench application. After 2 years, fruit were picked 158 (commercial harvest), 172 and 181 DAFB from treated and untreated trees, with fruit taken at commercial harvest being stored in air at 2 °C and 90% R.H. During ripening and after 5 and 7 months of storage, treated and untreated apples were analysed for odour-active volatiles, by using either static or dynamic headspace samplings and capillary gas chromatography. The results were expressed in terms of Odour Units (Uo) in order to relate the relative importance of each compound to overall aroma. The average Uo values at harvest and after storage showed that only half of the monitored volatiles were present in concentrations great enough to contribute to overall aroma. PBZ treatment enhanced the ripening processes, which are associated with volatile evolution at harvest and after 5 months of air storage, and may have a specific effect on the metabolism of pentyl acetate and ethyl butanoate.

Influence of water scrubbing on the production of volatile compounds and on sensory characteristics of ‘Golden Delicious’ apples stored in controlled atmosphere☆

The effect of the washing of the storage room atmosphere with water (water scrubbing) on the volatile production and on sensory quality of Golden Delicious apples (Malus domestica Borkh.) stored in controlled atmosphere (CA) was investigated. Atmospheres from control and water-scrubbed rooms were analyzed for ethylene and volatile compound composition over a 30-week storage period and, at the end of this period, the apples from the two storage modes were left to ripen at ambient temperature. The ready-to-eat ripe fruit were subjected to sensory analysis and their volatile composition was assessed by capillary gas chromatography. Water scrubbing advanced the ripening processes in Golden Delicious apples: water-scrubbed fruit had more soluble solids, less titratable acidity, were less firm and more yellow. The differences between the fruit stored in the two rooms were perceived in the sensory analysis: water-scrubbed fruit were assessed sweeter and more aromatic than control fruit, while the latter were judged sourer and firmer. Water scrubbing did not reduce the concentration of ethylene and of other volatiles in the room atmosphere, but enhanced the production of selected compounds during storage (23-methylbutyl acetate, (E)-2-hexenol, hexyl acetate) and after poststorage ripening (pentyl acetate, butyl butanoate, octyl propanoate).

Relationship Between Texture Sensory Profiles and Optical Properties Measured by Time-Resolved Reflectance Spectroscopy During Post-Storage Shelf Life of ‘Braeburn’ Apples

Abstract ‘Braeburn’ apples from three harvests after 6-month storage in controlled atmosphere were measured at 670 nm by time-resolved reflectance spectroscopy (TRS), ranked on decreasing μa670 (increasing maturity), classified as less (LeM), medium and more mature (MoM), randomised into three batches per harvest and analysed after 1, 8 and 14 days of shelf life. LeM and MoM apples were measured in the 630-900 nm range by TRS, and analysed for sensory profile (firm, crispy, juicy, mealy) and pulp mechanical characteristics (firmness, stiffness, energy-to-rupture). All data were processed by Principal Component Analysis (PCA). According to sensory intensity scores, fruits were either divided into five classes (very low – VL; low – L; medium – M; high – H; very high – VH) separately for every attribute, or clustered into four groups, each one representing a specific sensory profile. The absorption spectra showed a maximum at 670 nm (chlorophyll-a) and μa670 was higher in the VH class for firm, crispy and juicy and in the VL and L classes for mealy. The scattering spectra had a decreasing trend with the wavelength increase, and μs’ values were lower in the VH class for firm and crispy, and higher in the VH class for mealy and in the VL ones for juicy. PCA underlined that μs’ values were negatively related to firmness and μa670, and that μa690, μa730, μa830, μa850 and μa900 were opposed to mealiness. PC scores differed among the four sensory profiles and increased from VL to VH classes for firmness, crispiness and juiciness and from VH to VL classes for mealiness.

Time-resolved reflectance spectroscopy for nondestructive assessment of fruit and vegetable quality

In the majority of food and feed, due to the microscopic spatial changes in the refractive index, visible (VIS) and near infrared (NIR) light undergoes multiple scattering events and the overall light distribution is determined more by scattering rather than absorption. Conventional steady state VIS/NIR reflectance spectroscopy can provide information on light attenuation, which depends both on light absorption and light scattering, but cannot discriminate these two effects. On the contrary, time-resolved reflectance spectroscopy (TRS) provides a complete optical characterisation of diffusive media in terms of their absorption coefficient and reduced scattering coefficient. From the assessment of the absorption and reduced scattering coefficients, information can then be derived on the composition and internal structure of the medium. Main advantages of the technique are the absolute non-invasiveness, the potentiality for non-contact measurements, and the capacity to probe internal properties with no influence from the skin. In this work we review the physical and technical issues related to the use of TRS for nondestructive quality assessment of fruit and vegetable. A laboratory system for broadband TRS, based on tunable mode-locked lasers and fast microchannel plate photomultiplier, and a portable setup for TRS measurements, based on pulsed diode lasers and compact metal-channel photomultiplier, will be described. Results on broadband optical characterisation of fruits and applications of TRS to the detection of internal defects in pears and to maturity assessment in nectarines will be presented.