Food Technology Research Unit

The inhibiting effect of ascorbic acid, citric acid and sodium chloride on Polyphenoloxidase (PPO) of Golden Delicious apple cubes was studied. Dipping in ascorbic acid (0.2-10 g/L range) and in NaCl (0.2-1 g/L range) solutions for 5 min increases the PPO activity. Citric acid solutions (0.2-10 g/L range) have little or no inhibition of PPO. A 90-100% PPO inhibition was obtained with a 5 min dip in mixtures of ascorbic acid and citric acid (10 + 2 g/L), and of ascorbic acid and sodium chloride (10 + 0.5 g/L).

ABSTRACT: A novel method was developed to extend the shelf life and improve the quality of fresh‐cut produce. Edible coatings and films were made from apple puree with various concentrations of fatty acids, fatty alcohols, beeswax, and vegetable oil. Apple pieces were coated with solutions or wrapped in preformed films. Changes in moisture content and color were measured during storage. Increasing concentrations of lipids significantly improved the moisture barrier properties of films. Water vapor permeability varied from 69 to 325 g mm/kPa d m 2 . Apple‐based wraps significantly reduced moisture loss and browning in fresh‐cut apples. Color was preserved for 12 d at 5 °C. Wraps were significantly more effective than coatings.

BACKGROUND: Apparent Amylose Content (AAC), regulated by the Waxy gene, represents the key determinant of rice cooking properties. In occidental countries high AAC rice represents the most requested market class but the availability of molecular markers allowing specific selection of high AAC varieties is limited. RESULTS: In this study, the effectiveness of available molecular markers in predicting AAC was evaluated in a collection of 127 rice accessions (125 japonica ssp. and 2 indica ssp.) characterized by AAC values from glutinous to 26%. The analyses highlighted the presence of several different allelic patterns identifiable by a few molecular markers, and two of them, i.e., the SNPs at intron1 and exon 6, were able to explain a maximum of 79.5% of AAC variation. However, the available molecular markers haplotypes did not provide tools for predicting accessions with AAC higher than 24.5%. To identify additional polymorphisms, the re-sequencing of the Waxy gene and 1kbp of the putative upstream regulatory region was performed in 21 genotypes representing all the AAC classes identified. Several previously un-characterized SNPs were identified and four of them were used to develop dCAPS markers. CONCLUSIONS: The addition of the SNPs newly identified slightly increased the AAC explained variation and allowed the identification of a haplotype almost unequivocally associated to AAC higher than 24.5%. Haplotypes at the waxy locus were also associated to grain length and length/width (L/W) ratio. In particular, the SNP at the first intron, which identifies the Wxa and Wxb alleles, was associated with differences in the width of the grain, the L/W ratio and the length of the kernel, most likely as a result of human selection.

We present a new interaction geometry for optical Ramsey fringes comprised of four traveling waves instead of the three usual standing waves. First, we demonstrate experimentally that the new method leads to an improved contrast, using the optothermal detection of the vibrational excitation of ${\mathrm{SF}}_{6}$ in a supersonic beam illuminated by a waveguide ${\mathrm{CO}}_{2}$ laser. Second, we give a simple theoretical description of the method, using evolution matrices of spinors and pseudospin-vector representations of these spinors. Finally, we introduce strong-field density-matrix diagrams to discuss the differences between the various interaction geometries as well as between the Ramsey fringes and the usual stimulated photon echoes.

Summary This paper proposes a review of some alternative approaches for food stabilisation and shelf life prolonging (based on the use of natural compounds and/or non‐thermal techniques). After a brief description of food structure implication on the way of using the alternative approaches, two paragraphs summarise the topics of natural molecules (essential oils, lysozyme, lactoferrin and lactoperoxidase system, fatty acids, chitosan) and non‐thermal approaches (high hydrostatic and homogenisation pressures, pulsed electric fields, high power ultrasound and irradiation). Finally, the last sections deal with the use of combined hurdles (along with the proposal of three possible modes of action of a multi‐target preservation), the mathematical approaches for shelf life evaluating and some critical issues to be addressed in the future for a real scaling up of the proposed techniques.

This paper presents a method for mapping the nitrogen (N) status in a maize field using hyperspectral remote sensing imagery. An airborne survey was conducted with an AISA Eagle hyperspectral sensor over an experimental farm where maize (Zea mays L.) was grown with two N fertilization levels (0 and 100 kg N ha−1) in four replicates. Leaf and canopy field data were collected during the flight. The nitrogen (N) status has been estimated in this work based on the Nitrogen Nutrition Index (NNI), defined as the ratio between the leaf actual N concentration (%Na) of the crop and the minimum N content required for the maximum biomass production (critical N concentration (%Nc)) calculated through the dry mass at the time of the flight (Wflight). The inputs required to calculate the NNI (i.e., %Na and Wflight) have been estimated through regression analyses between field data and remotely sensed vegetation indices. MCARI/MTVI2 (Modified Chlorophyll Absorption Ratio Index/Modified Triangular Vegetation Index 2) showed the best performances in estimating the %Na (R2 = 0.59) and MTVI2 in estimating the Wflight (R2 = 0.80). The %Na and the Wflight were then mapped and used to compute the NNI map over the entire field. The NNI map agreed with the NNI estimated using field data through traditional destructive measurements (R2 = 0.70) confirming the potential of using remotely sensed indices to assess the crop N condition. Finally, a method to derive a pixel based variable rate N fertilization map was proposed as the difference between the actual N content and the optimal N content. We think that the proposed operational methodology is promising for precision farming since it represents an innovative attempt to derive a variable rate N fertilization map based on the actual crop N status from an aerial hyperspectral image.

The antioxidant properties of simple carbohydrates were studied in a chemical system. Hydroxyl radicals generated by a Fenton reaction induce damage on simple carbohydrates with a consequent free radical scavenging activity. Carbohydrate activities were measured by different methods as spin-trapping of hydroxyl radical and electron paramagnetic resonance detection and 1,1-diphenyl-2-picrylhydrazyl quenching. Carbohydrate damage was evaluated in a Fenton system by measuring the reactive substances to thiobarbituric acid, by their decreased detection with an HPLC test, and by a gas chromatographic determination of formic acid from sugar oxidation. Different intensities of damage and scavenging were found according to molecular structure, and some hyphotheses on the carbohydrate action against free radicals were attempted. The assayed disaccharides were shown to be more active toward and less damaged by hydroxyl radical than monosaccharides.

The antioxidant content and activity of commercial tomato products differing in variety and processing were studied. Two procedures for extracting hydrophilic and lipophilic antioxidants, namely, two-step 0.1 M phosphate buffer (pH 3.0 and 7.4) extraction and tetrahydrofuran extraction followed by petroleum ether fractionation, were developed. Carotenoids (lycopene, beta-carotene, and lutein) and ascorbic acid were analyzed by HPLC with spectrophotometric and electrochemical detectors, respectively. Total phenolics were determined by using the Folin-Ciocalteu reagent. The antioxidant activity was studied by the following three model systems: (a) the xanthine oxidase (XOD)/xanthine system, which generates superoxide radical and hydrogen peroxide; (b) the myeloperoxidase (MPO)/NaCl/H(2)O(2) system, which produces hypochloric acid; and (c) the linoleic acid/CuSO(4) system, which promotes lipid peroxidation. Results showed that the hydrophilic and lipophilic fractions of all tomato products were able to affect model reactions, whatever reactive oxygen species and catalysts were used to drive oxidation. In the XOD/xanthine system both the hydrophilic and lipophilic fractions displayed an inhibitory activity. The hydrophilic fractions were more effective (I(50) ranging from 680 to 3200 microg, dry weight) than the lipophilic fractions (I(50) ranging from 4000 to 7750 microg, dry weight). In the MPO/NaCl/H(2)O(2) system the hydrophilic fractions inhibited oxidation (I(50) ranging from 2300 to 2900 microg, dry weight), whereas the lipophilic fractions had a lower inhibitory effect at the same concentration. Conversely, in the copper-catalyzed lipid peroxidation only the lipophilic fractions were effective (I(50) ranging from 1030 to 2100 microg, dry weight), whereas the hydrophilic fractions had a pro-oxidant effect in the same concentration range. The extent of inhibition varied according to the tomato sample in the superoxide and hydrogen peroxide generating system and in lipid peroxidation, but was substantially the same in the HClO generating system. Fresh tomato varieties differed considerably in the antioxidant activities of their hydrophilic and lipophilic fractions. Processed tomatoes showed a significantly lower antioxidant activity than fresh tomatoes in their hydrophilic fractions but had a high antioxidant activity in their lipophilic fractions. Because the oxidative reactions produced by the above-mentioned model systems are also involved in the pathogenesis of several chronic diseases, the antioxidant activity of tomato fractions might be related to their in vivo activity. Hence, these measurements may be used for optimizing tomato technologies.

Inflammation derived from pathogen infection involves the activation of toll-like receptor (TLR) signaling. Despite the established immunomodulatory activities of probiotics, studies relating the ability of such bacteria to inhibit the TLR signaling pathways are limited or controversial. In a previous study we showed that Lactobacillus amylovorus DSM 16698T, a novel lactobacillus isolated from unweaned pigs, protects the intestinal cells from enterotoxigenic Escherichia coli (ETEC) K88 infection through cytokine regulation. In the present study we investigated whether the ability of L. amylovorus to counteract the inflammatory status triggered by ETEC in intestine is elicited through inhibition of the TLR4 signaling pathway. We used the human intestinal Caco-2/TC7 cells and intestinal explants isolated from 5 week-old crossbreed Pietrain/Duroc/Large-White piglets, treated with ETEC, L. amylovorus or L. amylovorus cell free supernatant, either alone or simultaneously with ETEC. Western blot analysis showed that L. amylovorus and its cell free supernatant suppress the activation of the different steps of TLR4 signaling in Caco-2/TC7 cells and pig explants, by inhibiting the ETEC induced increase in the level of TLR4 and MyD88, the phosphorylation of the IKKα, IKKβ, IκBα and NF-κB subunit p65, as well as the over-production of inflammatory cytokines IL-8 and IL-1β. The immunofluorescence analysis confirms the lack of phospho-p65 translocation into the nucleus. These anti-inflammatory effects are achieved through modulation of the negative regulators Tollip and IRAK-M. We also found that L. amylovorus blocks the up-regulation of the extracellular heat shock protein (Hsp)72 and Hsp90, that are critical for TLR4 function. By using anti-TLR2 antibody, we demonstrate that TLR2 is required for the suppression of TLR4 signaling activation. These results may contribute to develop therapeutic interventions using L. amylovorus in intestinal disorders of piglets and humans.

Changes in the proportions of the various lipid components in spermatozoa were investigated throughout the reproductive period (24-72 wk of age) of male chickens. Sperm motility and in vivo fertility were also measured, and correlation coefficients with the lipid values were determined. The proportion of total phospholipid (PL) increased to reach a maximum value at 39 wk and decreased significantly thereafter. The relative content of free cholesterol and triacylglycerols showed no change in spermatozoa during aging or in relation to fertility values; free fatty acids and cholesterol esters increased continuously with age. Of the various PL classes, phosphatidylserine and phosphatidylcholine displayed a pattern of changes with age positively and negatively, respectively, in relation to the changes of fertility. The proportion of phosphatidylethanolamine had significantly decreased by the end of the reproductive period. The proportions of C16:0, C18:0, and C18:1n-9 within the PL of the spermatozoa increased with age, and those of C20:4n-6, C22:4n-6, and C22:6n-3 decreased. Positive correlations were found between fertility and total PLs, phosphatidylserine, and PL-bound C20:4n-6 and C22:4n-6; a negative correlation was found between fertility and phosphatidylcholine. Motility was positively correlated with the level of PL and negatively with that of free cholesterol; it was also positively correlated with the levels of C22:4n-6 and C22:6n-3 and negatively with those of C16:0, C18:0, and C18:1n-9. The results suggest that the lipid and fatty acid compositions of spermatozoa may be important predictors of fertility.

A chemical and bioactive quality evaluation of phytochemicals content of 10 eggplant lines and three allied species (S. sodomaeum, S. aethiopicum and S. integrifolium) was performed. The eggplant lines were divided into the two subgroups of delphinidin-3-rutinoside (D3R) and nasunin (NAS) typologies, on the basis of the anthocyanin detected in their fruit skin. The allied species had higher glycoalkaloids content, lower soluble solids and PPO activity and absence of anthocyanins compared to the eggplant lines; S. sodomaeum stood out for high phenols content. Orthogonal contrast revealed a higher sugar content and low PPO activity in NAS- compared to D3R-typologies, whereas higher chlorogenic acid and anthocyanin contents were present in D3R-typologies. The main effect of the ripening was a decrease in phenols and in the PPO activity, not evidenced in S. sodomaeum, and an increase of glycoalkaloids in overripe fruits. A good relationship was found between superoxide anion scavenging capacity and chlorogenic acid. This study highlighted the pattern of accumulation, also evidencing variations, of several phytochemicals during the eggplant fruit development and ripening.

The exchange of sugar components in cherry, apricot and peach with the osmotic syrup during osmotic dehydration was analyzed. Sugar exchange dynamics between the syrup and the fruits was found to be related not only to the flux of sugars from the syrup into the fruit, but is affected also by the individual sugars originally present in the fruit. The exchange is also dependent on the species of fruit, the relative diffusivity of the sugars and enzymatic activity within the fruit.

Summary In order to assess the effect of genotype, location and their interaction on total phenolic content (TPC) of chemical extracts, the whole grains of durum and soft wheat, oat, barley and triticale were evaluated. Data showed differences in phenolic content of chemical extracts among cereal species and the analysis of variance confirmed the key role of location. Besides TPC and trolox equivalent antioxidant capacity (TEAC) values assessed by chemical extraction were compared with those obtained with an in vitro digestive enzymatic extraction. Differences were found between methanolic and enzymatic extracts, and data confirmed that enzymatic technique enhanced extraction of antioxidants but pointed out lesser differences among cereal types. The breads obtained by flours enriched with different levels of bran were also evaluated. Chemical extracts highlighted the increasing levels of antioxidants according to bran enrichments, without pointing out changes caused by baking. The enzymatic extraction instead did not show differences regarding to bran enrichments, but documented a loss in antioxidant properties of breads in respect to corresponding flours. On the other hand the scarce differences between flours and corresponding breads did not allow asserting that baking modified the TPC and TEAC, independently of the extraction methods used. Indeed, during baking process, also the observed phenolic acids profile variations did not vary the antioxidant properties of breads.

In this work the combination of active coating and modified-atmosphere packaging (MAP) was used to prolong the shelf life of Fior di Latte cheese. The active coating was based on sodium alginate (8% wt/vol) containing lysozyme (0.25 mg/mL) and EDTA, disodium salt (Na(2)-EDTA, 50 mM). The MAP was made up of 30% CO(2), 5% O(2), and 65% N(2). The speed of quality loss for the Fior di Latte cheese, stored at 10 degrees C, was assessed by monitoring pH and weight loss, as well as microbiological and sensorial changes. Results showed that the combination of active coating and MAP improved Fior di Latte cheese preservation, increasing the shelf life to more than 3 d. In addition, the substitution of brine with coating could allow us to gain a double advantage: both preserving the product quality and reducing the cost of its distribution, due to the lower weight of the package.

In Western societies, the incidence of diet-related diseases is progressively increasing due to greater availability of hypercaloric food and a sedentary lifestyle. Obesity, diabetes, atherosclerosis, and neurodegeneration are major diet-related pathologies that share a common pathogenic denominator of low-grade inflammation. Functional foods and nutraceuticals may represent a novel therapeutic approach to prevent or attenuate diet-related disease in view of their ability to exert anti-inflammatory responses. In particular, activation of intestinal T regulatory cells and homeostatic regulation of the gut microbiota have the potential to reduce low-grade inflammation in diet-related diseases. In this review, clinical applications of polyphenol-rich functional foods and nutraceuticals in postprandial inflammation, obesity, and ageing will be discussed. We have placed special emphasis on polyphenols since they are broadly distributed in plants.

1. Ascorbate oxidase has been isolated from the green squash Cucurbita pepo medullosa by a new purification method. Furthermore a low-molecular-weight copper protein containing one type-1 copper/20000 Mr could be separated during the purification of the oxidase. The six-step procedure developed improved the yield of ascorbate oxidase by a factor of 2.5. The method is well reproducible and a constant value of 8 Cu (7.95 +/- 0.1/140000 Mr) has been established. By ultracentrifugal and electrophoretic criteria the enzyme preparations have been found to be homogeneous. They exhibited a specific activity of 3930 +/- 50 units/mg protein or 1088 +/- 15 units/microgram copper. 2. The pure enzyme is characterized by the following optical purity indices: A280/A610 = 25 +/- 0.5, A330/A610 = 0.65 +/- 0.05 and A610/A500 = 7.0 +/- 0.25. The molar absorption coeffient of the characteristic absorption maximum at 610 nm (oxidized minus reduced) amounts of 9700 M-1 cm-1 . 3. Computer simulations of the electron paramagnetic resonance (EPR) spectra of the oxidized enzyme reveal the following parameters: for the type-1 (blue) copper gz = 2.227, gy = 2.058, gx = 2.036; Az = 5.0 mT, Ay = Ax = 0.5 mT, for the type-2 (non-blue) copper g parallel to = 2.242, g perpendicular = 2.053; A parallel to = 19.0 mT, A perpendicular 0.5 mT. Out of the eight copper atoms present in the oxidase four are detectable by EPR. Of these, three belong to the type-1 class, and one to the type-2 class, as demonstrated by computer simulations of the EPR spectra. 4. To achieve full reduction of the enzyme, as measured by bleaching of the blue chromophore, four equivalents of L-ascorbate or reductase must be added in the absence of molecular oxygen. Upon reduction of the enzyme the fluorescence at 330 nm (lambda max ex = 295 nm) is enhanced by a factor of 1.5 to 1.75. The reduced enzyme is readily reoxidized by dioxygen, ferricyanide or hydrogen peroxide. It binds two molecules of hydrogen peroxide in the oxidized state (1/type-3 Cu pair), which can be monitored by a characteristic increase of the absorbance around 310 nm (delta epsilon = 1000 +/- 50 M-1 cm-1). Corresponding changes in EPR and fluorescence spectra have not been detected.

Eggplant berries are a source of health-promoting metabolites including antioxidant and nutraceutical compounds, mainly anthocyanins and chlorogenic acid; however, they also contain some anti-nutritional compounds such as steroidal glycoalkaloids (SGA) and saponins, which are responsible for the bitter taste of the flesh and with potential toxic effects on humans. Up to now, Quantitative Trait Loci (QTL) for the metabolic content are far from being characterized in eggplant, thus hampering the application of breeding programs aimed at improving its fruit quality. Here we report on the identification of some QTL for the fruit metabolic content in an F2 intraspecific mapping population of 156 individuals, obtained by crossing the eggplant breeding lines "305E40" × "67/3." The same population was previously employed for the development of a RAD-tag based linkage map and the identification of QTL associated to morphological and physiological traits. The mapping population was biochemically characterized for both fruit basic qualitative data, like dry matter, °Brix, sugars, and organic acids, as well as for health-related compounds such chlorogenic acid, (the main flesh monomeric phenol), the two peel anthocyanins [i.e., delphinidin-3-rutinoside (D3R) and delphinidin-3-(p- coumaroylrutinoside)-5-glucoside (nasunin)] and the two main steroidal glycoalkaloids, solasonine, and solamargine. For most of the traits, one major QTL (PVE ≥10%) was spotted and putative orthologies with other Solanaceae crops are discussed. The present results supply valuable information to eggplant breeders on the inheritance of key fruit quality traits, thus providing potential tools to assist future breeding programs.

In the present study, we investigated the content and profile of polyphenols (PPH), ascorbic acid (AA), the Folin–Ciocalteu index (FCI), and antioxidant activity (1,1-diphenyl-2-picrylhydrazyl (DPPH) and peroxyl radical (ROO)) variation during three different plant growth stages (sprouts, microgreens and baby leaves) of two broccoli types, the traditional Sicilian sprouting broccoli landrace (‘Broccolo Nero’) and the broccoli standard (‘Cavolo broccolo Ramoso Calabrese’), and the standard commercial cultivar of kale (‘Cavolo Lacinato Nero di Toscana’). All biomasses collected were freeze-dried for PPH, AA, FCI, DPPH and ROO analysis. The highest polyphenol content was observed for ‘Broccolo Nero’ (BN) and ‘Cavolo Broccolo Ramoso Calabrese’ (CR), and generally sprouts showed significantly higher values compared to the microgreens and the baby leaves. The AA, FCI, DDPH and ROO significantly vary with regards to the cultivar and the plant growth stage, showing interaction between the two experimental factors analyzed. The interaction detected showed higher values for the antioxidant traits of the proposed novel food, especially for the two broccoli cultivars in the sprout growth stage in comparison to the microgreens and baby leaves. Our results suggest that the antioxidant activity is partially dependent on kaempferol and apigenin. The PPH compounds showed the highest values of kaempferol and apigenin for ‘Broccolo nero’, whereas for the other two cultivars studied, only kaempferol was the main compound represented. The data acquired are of interest for increasing the healthy traits of the novel food proposed showing the contribution offered by the neglected LRs until now underutilized and at risk of extinction. The germplasm conserved in several world genebanks could support and diversify the organic vegetable items, providing us with added-value products for organic food supply chains.

Conference pears (Pyrus communis L.) were treated with 25 and 50 nL L(-1) 1-methylcyclopropene (1-MCP) at -0.5 degrees C for 24 h, then stored for up to 22 weeks in air (NA) and controlled atmosphere (CA). After 7 and 14 weeks of storage, fruits were retreated with 1-MCP. After 7, 14, and 22 weeks of storage, fruits were kept for up to 7 days at 20 degrees C in air for poststorage ripening. The effects of 1-MCP treatment declined with duration of storage in both storage atmospheres, indicating that retreatments had little additional effects on subsequent ripening. Ethylene production was lower and firmness was higher in 50 nL L(-1) fruits, while the 25 nL L(-1) dose was not very different from the control. Development of superficial scald was not prevented by 1-MCP treatments, but the severity of the symptoms was influenced. The 1-MCP effects were perceivable on texture (juiciness) and flavor. Control fruit and 25 nL L(-1) fruit reached their best sensory quality after 14 weeks of storage, while 50 nL L(-1) fruit reached the same sensory quality later, keeping a fresh flavor when the quality of control fruit declined and became watery or grainy. The fresh flavor in 50 nL L(-1) fruit was probably due to the presence below the odor detection threshold concentrations of the volatile compounds responsible for the "ripe pear" aroma, mainly of butanol and ethyl butanoate. CA prolonged or enhanced the effects of 1-MCP; 1-MCP cannot substitute for CA but can reinforce the CA effects.

Abstract The authors are reviewing here the development and the application of the nondestructive spectrophotometric analytical techniques applied to the agricultural commodities. Following a short description of the theoretical bases of this technique, the most significant applications are reviewed leading to the evolution of the first generation of instruments based on such principles. The applications of the specific instruments developed for on‐line measurements are summarized. The Grain Quality Analyzers actually marketed and their use in the determination of a wide range of components in foods are described. The experience gained by the research developed using such instruments has generated a new series of computerized instruments allowing for new methodologies and applications that are discussed and reviewed here. The state of the art and the development trends are briefly discussed, particularly referring to the research aimed to the extension of this technique to evaluate different chemical compounds in foods, to use as quality indices for agronomic, processing, and marketing purposes.