Serena Polverigiani

Microbial Diversity of Type I Sourdoughs Prepared and Back‐Slopped with Wholemeal and Refined Soft (Triticum aestivum) Wheat Flours

The fermentation of type I sourdough was studied for 20 d with daily back-slopping under laboratory and artisan bakery conditions using 1 wholemeal and 2 refined soft wheat (Triticum aestivum) flours. The sourdough bacterial and yeast diversity and dynamics were investigated by plate counting and a combination of culture-dependent and culture-independent PCR-DGGE approach. The pH, total titrable acidity, and concentration of key organic acids (phytic, lactic, and acetic) were measured. Three flours differed for both chemical and rheological properties. A microbial succession was observed, with the atypical sourdough species detected at day 0 (i.e. Lactococcus lactis and Leuconostoc holzapfelii/citreum group for bacteria and Candida silvae and Wickerhamomyces anomalus for yeasts) being progressively replaced by taxa more adapted to the sourdough ecosystem (Lactobacillus brevis, Lactobacillus alimentarius/paralimentarius, Saccharomyces cerevisiae). In mature sourdoughs, a notably different species composition was observed. As sourdoughs propagated with the same flour at laboratory and artisan bakery level were compared, the influence of both the substrate and the propagation environment on microbial diversity was assumed.

Occurrence of antibiotic resistance genes in the fecal DNA of healthy omnivores, ovo‐lacto vegetarians and vegans

SCOPE The effects of long-term omnivore, ovo-lacto vegetarian and vegan diets on the occurrence of 12 antibiotic resistance (AR) genes in the human gut were studied. METHODS AND RESULTS The feces of 144 healthy volunteers recruited from Turin, Bari, Bologna, and Parma were screened for the occurrence of genes conferring resistance to tetracyclines, macrolide-lincosamide-streptogramin B, vancomycin, and β-lactams. Overall, erm(B), tet(W) and tet(M) were detected at the highest frequency. A low effect from the diet on the AR gene distribution emerged, with tet(K) and vanB occurring at a lower and higher frequency in vegans and omnivores, respectively. A correlation of the intake of eggs, milk from animal sources and cheese with an increased occurrence of tet(K) was observed, together with a higher incidence of vanB in consumers of eggs, poultry meat, fish and seafood. When the detection frequencies of AR genes in volunteers from Bari and the other sites were comparatively evaluated, a north-to-south gradient was observed, whereas no effect of sex or age was highlighted. Except for tet(K), a negligible three-factor interaction was seen. CONCLUSION A high impact of the geographical location on AR gene distribution was seen in the cohort of subjects analyzed, irrespective of their dietary habits.

Organic Wastes Use in Horticulture: Influences on Nutrient Supply and Apple Tree Growth

The application of fertilizers derived from agroindustrial by-products, represents an interesting opportunity in organic farming. The composition of such inputs includes complex molecules, which strongly influence their effectiveness in providing the optimal nutrient availability and improving crop performances. The aim of the present study was to determine the nutrient release rate of different organic fertilizers and amendments and their effects on shoot growth, fruit production, leaf nutritional status, root biomass and morphology. In a two-years pot trial, two organic fertilizers produced with dried fungal biomass (DFB) and vinasse of sugar beet pulp (VN) and two amendments obtained from fermented animal sewage (SE) and composted olive husks plus grapevine waste (OG), were applied on apple rooted cuttings. One set of plant were not fertilised and acted as Control. The application of DFB, VN and SE increased nitrogen concentration in the soil and in the leaves, supported higher fruit number and enhanced plant growth above and below ground compared to OG and Control. The effect on root growth was positively correlated with nitrogen mineralization rate. For OG treatment, soil electric conductivity negatively influenced root branching frequency, indicating a potential risk of stress due to salinity excess. Original Research Article Polverigiani et al.; IJPSS, Article no. IJPSS.2014.003 359

Oil Characteristics of Four Palestinian Olive Varieties

Olive oil represents an important source of income for Palestinian farmers in local, national and international markets. Sometimes, olive oil produced in local climatic conditions, does not achieve the International Olive Council (IOC) trade standards so that international markets are precluded. The oil chemical composition and sensory profile of four Palestinian olive varieties (Nabali Baladi, Nabali Mohassan, Souri and K18) were characterized in 2010 throughout an in situ evaluation. Most of the physicchemical characteristics and the fatty acid composition of the varieties met the International Olive Council trade standards (IOC-TS) for extra virgin olive oils. Values of K270 for Nabali Baladi and linolenic acid for Souri slightly exceeded the limit. Eicosanoic acid exceeded the IOC-TS limits in the oils of all considered varieties. Among the sterols, the Δ-7-stigmastenol resulted too high for Nabali Baladi and Souri. Sensory profile for the tested varieties showed a reminiscence of tomato or artichoke and light to medium bitter and pungent sensations. Results represent an important baseline reference for further studies about oil composition and quality of the main Palestinian olive germplasm and provide indication of potential critical points to be controlled in order to ensure the full achievement of IOC-TS and access international markets.