Emanuele Marconi

Composition and Utilization of Barley Pearling By-Products for Making Functional Pastas Rich in Dietary Fiber and β-Glucans

ABSTRACT Pearling by-products and the pearled products of two commercial stocks of hulled barley, pearled according to an industrial process consisting of five consecutive pearling steps, were analyzed for β-glucans, dietary fiber (total, soluble, and insoluble), protein, lipid, ash, and digestible carbohydrate. The data showed that the pearling flour fractions, abraded in the fourth and fifth hullers, contained interesting amounts of β-glucans (3.9–5.1% db) from a nutritional point of view. These fractions were subsequently enriched in β-glucans using a milling-sieving process to double β-glucan content (9.1–10.5% db). Functional pastas, enriched with β-glucans and dietary fiber, were produced by substituting 50% of standard durum wheat semolina with β-glucan-enriched barley flour fractions. Although darker than durum wheat pasta, these pastas had good cooking qualities with regard to stickiness, bulkiness, firmness, and total organic matter released in rinsing water. The dietary fiber (13.1–16.1% wb) an...

Influence of gluten proteins and drying temperature on the cooking quality of durum wheat pasta

ABSTRACT It is well known that gluten plays a major role in determining cooking quality in durum wheat pasta. This work is an attempt to systematically elucidate the role of gluten quantity and nature in determining cooking quality as a function of the drying cycle used in the manufacturing process. Gluten and starch were fractionated from two durum wheat cultivars possessing good and poor gluten quality. Either of them were then added back to the original base semolina to alter its protein content and to produce two semolina series with identical protein contents. Semolinas were processed into pasta and dried following three drying programs (low, medium, and high temperature). Cooking quality was determined with sensorial, chemical, and instrumental methods. The results indicate that optimum cooking time is governed by gluten quality. The positive effect on cooking quality of increasing gluten contents and of the application of HT drying is evident in weak gluten samples, but it is not significant in the...

Kernel Properties and Pasta-Making Quality of Five European Spelt Wheat (Triticum spelta L.) Cultivars

ABSTRACT The kernel characteristics and composition, milling performance, protein quality, and alveograph parameters of five spelt cultivars grown in European countries were determined in relation of their utilization in pasta products. Long pasta was manufactured and chemically characterized, and its quality was assessed by sensory and chemical tests. Protein and fat contents were high in the grains (15.7 and 4.4% db, mean value, respectively). Total fiber varied from 10.5 to 14.9% db. The average β-glucan content was 1.2% db. The milling performance as determined by yield, damaged starch, ash, and particle-size distribution in the flour was uniform among the five cultivars. The results of the SDS sedimentation and gluten index tests indicated that spelt gluten strength was low, and this was confirmed by the alveograph test. Sensory and chemical evaluations of the pastas, however, indicated that spelt is suitable for obtaining good-quality pasta. The combination of the high protein content and the high-t...

Heat-treated milk differentiation by a sensitive lactulose assay

Abstract A sensitive enzymatic assay for determining lactulose (detection limit=2.5 mg/l; RSD

Phenolic compounds and saponins in quinoa samples (Chenopodium quinoa Willd.) grown under different saline and nonsaline irrigation regimens.

Quinoa is a pseudocereal from South America that has received increased interest around the world because it is a good source of different nutrients and rich in antioxidant compounds. Thus, this study has focused on the effects of different agronomic variables, such as irrigation and salinity, on the phenolic and saponin profiles of quinoa. It was observed that irrigation with 25% of full water restitution, with and without the addition of salt, was associated with increases in free phenolic compounds of 23.16 and 26.27%, respectively. In contrast, bound phenolic compounds were not affected by environmental stresses. Saponins decreased if samples were exposed to drought and saline regimens. In situations of severe water deficit, the saponins content decreased 45%, and 50% when a salt stress was added. The results suggest that irrigation and salinity may regulate the production of bioactive compounds in quinoa, influencing its nutritional and industrial values.

Rapid determination of lactulose in milk by microdialysis and biosensors

A simple and rapid flow system for the determination of lactulose in milk samples was developed. It is based on the hydrolysis of lactulose to galactose and fructose by the enzyme beta-galactosidase immobilised in a reactor. The amount of fructose produced was measured with an electrochemical biosensor based on the fructose dehydrogenase enzyme, K3[Fe(CN)6] as mediator and a platinum based electrochemical transducer. Parameters such as the enzyme immobilisation in the reactor and under the electrode surface, the lifetime of the beta-galactosidase reactor and of the dehydrogenase biosensor and the flow parameters were studied and optimised. Fructose was determined in the range 1 x 10(-6)-5 x 10(-3) mol l-1 with an RSD of about 2% and a detection limit of 5 x 10(-7) mol l-1. The use of a microdialysis probe as the sampling system permitted the direct measurement of lactulose in milk samples without pre-treatment in the range 1 x 10(-5)-5 x 10(-3) mol l-1. The sensitivity of the procedure allowed pasteurised, UHT and in-container sterilised milk to be distinguished.

Spelt (Triticum spelta L.) pasta quality: Combined effect of flour properties and drying conditions

ABSTRACT Three spelt genotypes (Rouquin, Redoute, and HGQ Rouquin= Rouquin improved for gluten quality), each characterized by either high or low protein content, were processed to manufacture spaghetti, which was dried at both low (60°C) and high temperature (90°C) to assess the effects of flour properties and drying conditions on spelt pasta quality. Protein content in the spelt flour was considered low at ≈11.4% db and high at ≈13.5% db. Gluten properties, assessed by SDS sedimentation and gluten index values and by alveograph and farinograph parameters varied widely, ranging from poor for Redoute to very good for HGQ Rouquin. Pasta quality was assessed by determining color (L*, a*, and b* values), furosine, and cooking quality (stickiness, bulkiness, firmness, and total organic matter [TOM]). Furosine and color (a* and b* values) were significantly influenced by the intensity of the drying process. TOM and organoleptic judgement (OJ) showed that spelt pastas dried at low temperature, independent of th...

Development of Functional Spaghetti Enriched with Long Chain Omega-3 Fatty Acids

ABSTRACT Results concerning the production of spaghetti enriched in long chain (LC) n-3 polyunsaturated fatty acids (PUFA) and, in particular, eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA) are reported. Pasta enrichment was obtained by adding different amounts of integrator (0.6, 1.2, and 1.8%) containing EPA (C20:5 n-3) and DHA (C22:6 n-3) in a microencapsulated form to commercial semolina. The addition of 1.2% integrator yielded spaghetti that provides ≈20% of the recommended daily intake of LC n-3 PUFA with high sensorial acceptability and low loss of LC n-3 PUFA after cooking (<10%). Thus, spaghetti fortified with EPA+DHA could be used to increase consumption of LC n-3 PUFA and to decrease the dietary n-6/n-3 ratio.

Inulin-enriched pasta improves intestinal permeability and modifies the circulating levels of zonulin and glucagon-like peptide 2 in healthy young volunteers

Apart from the intestinal environment, inulin induces physiological effects, which includes a reduction in glucose and lipid concentrations and modulation of gastrointestinal motility through the release of different peptides. We hypothesized that inulin-enriched pasta may also improve small intestine permeability in relation to zonulin and glucagon-like peptide 2 (GLP-2) levels in healthy young subjects. Twenty healthy, young male volunteers completed a randomized, double-blind crossover study consisting of a 2-week run-in period and two 5-week study periods (11% inulin-enriched or control pasta), with an 8-week washout period in between. The intestinal barrier function was assessed by lactulose-mannitol excretion in urine. Zonulin values and GLP-2 release were evaluated by enzyme-linked immunosorbent assay. In the inulin group, the urinary lactulose recovery was significantly lower than the other 2 groups. There were no significant differences in urinary mannitol levels between groups. Accordingly, the lactulose-mannitol excretion ratio was significantly decreased in the inulin-enriched pasta group compared with the other 2 groups. The inulin-enriched pasta group had significantly lower zonulin serum values and significantly higher GLP-2 basal values when compared with the baseline and control pasta groups. The dietary use of inulin-enriched pasta preserves intestinal mucosal barrier functioning and modulates circulating levels of zonulin and GLP-2, suggesting that prebiotics could be used in the prevention of gastrointestinal diseases and metabolic disorders.

Comparative study on microwave and conventional methods for protein hydrolysis in food

SummaryA rapid microwave hydrolysis procedure was developed for amino acid determination in food. The hydrolysis was performed with 6M HCl in sealed vessels using a microwave digestion system.Bovine Serum Albumin was chosen as a model protein to compare its theoric amino acid sequence with the experimental results obtained after hydrolysis by both the traditional oven heating and the microwave methods. Furthermore the selected microwave methods were carried out on different food matrices (cheese and durum wheat) and the obtained data were compared with the traditional method results.This comparative study shows that the rapid microwave hydrolysis is as accurate and precise as the traditional hydrolysis for determining amino acids in food.