Polyphenolic profile of butterhead lettuce cultivar by ultrahigh performance liquid chromatography coupled online to UV-visible spectrophotometry and quadrupole time-of-flight mass spectrometry.

In the present study, the butterhead lettuce cultivar was analyzed by ultrahigh performance liquid chromatography (UHPLC) coupled online to diode array detection (DAD), electrospray ionization (ESI) and quadrupole time-of-flight mass spectrometry (QToF/MS) in the positive and negative ion mode in order to characterize its polyphenolic profile for the first time. The instrument acquisition mode MS was used to collect automatic and simultaneous information of exact mass at high and low collision energies of precursor ions as well as other ions produced as a result of their fragmentation. One hundred eleven phenolic compounds were identified in the acidified hydromethanolic extract of freeze-dried leaves of butterhead lettuce cultivar: 40 hydroxycinnamic acid derivatives, 21 hydroxybenzoic acid derivatives, 2 hydroxyphenylacetic acid derivatives, 18 flavonols, 9 flavones, one flavanone, 7 coumarins, one hydrolysable tannin and 12 lignans.

Characterization of phenolic compounds in green and red oak-leaf lettuce cultivars by UHPLC-DAD-ESI-QToF/MS using MS scan mode.

Lettuce (Lactuca sativa) is one of the most popular leafy vegetables in the world and constitutes a major dietary source of phenolic compounds with health-promoting properties. In particular, the demand for green and red oak-leaf lettuces has considerably increased in the last years but few data on their polyphenol composition are available. Moreover, the usage of analytical edge technology can provide new structural information and allow the identification of unknown polyphenols.

Lactic acid as potential substitute of acetic acid for dissolution of chitosan: preharvest application to Butterhead lettuce.

Chitosan must be dissolved in acid solution to activate its antimicrobial properties. The objectives of present study were to determine whether acetic and lactic acids used to dissolve chitosan would influence its effectiveness to control the native microflora of Butterhead lettuce at harvest and during postharvest storage (7-8 °C, 5 days). Chitosan was applied as a SINGLE DOSE (14, 10, 7, 3 or 0 days previous to harvest) or in SUCCESSIVE DOSES (at 14 + 10 + 7+3 + 0 days prior to harvest).

Freshly characterization and storability of mini head lettuces at optimal and abusive temperatures.

Selection of lettuce varieties less sensitive to quality deterioration and more tolerant to abusive temperatures during handling, transportation, and storage is essential to minimize economical and quality losses that affect both producers and consumers. This work was focused on the quality changes of four baby head lettuces (Lactuca sativa L.), two butter (red and green) and two oak-leaf (red and green) types, during storage at 0 ℃ and 10 ℃ for 10 days.

Oregano essential oil-pectin edible films as anti-quorum sensing and food antimicrobial agents.

Edible films can be used as carriers for antimicrobial compounds to assure food safety and quality; in addition, pathogenesis of food bacteria is related to a cell to cell communication mechanism called quorum sensing (QS). Oregano essential oil (OEO) has proved to be useful as food antimicrobial; however, its food applications can be compromised by the volatile character of its active constituents. Therefore, formulation of edible films containing OEO can be an alternative to improve its food usages.

Brewer's spent grain: characterization and standardization procedure for the enzymatic hydrolysis by Bacillus cereus strain.

An important way to reuse agroindustrial by-products and to produce added-value products consists of the production of protein hydrolysates. In the current study, we used Brewer's spent grain (BSG), mainly because of its availability and cost, as a substrate for the enzymatic hydrolysis by Bacillus cereus. First, the physicochemical and microbiological characterization of BSG batches from three varieties was carried out.

Effectiveness of edible coatings combined with mild heat shocks on microbial spoilage and sensory quality of fresh cut broccoli (Brassica oleracea L.).

Unlabelled: The use of edible coatings and mild heat shocks is proposed as postharvest treatments to prevent microbial deterioration of refrigerated broccoli. Minimally processed broccoli was coated with either chitosan or carboxymethyl-cellulose (CMC) combined or not with a previous application of a mild heat shock. The evolution of microbial populations (mesophilic, psycrotrophic, Enterobacteriaceae, molds and yeast, and lactic acid bacteria) was studied during 20 d of storage and fitted to Gompertz and logistic models.

Antimicrobial effectiveness of bioactive packaging materials from edible chitosan and casein polymers: assessment on carrot, cheese, and salami.

Antimicrobial packaging is one of the most promising active packaging systems for controlling spoilage and pathogenic microorganisms. In this work, the intrinsic antimicrobial properties of chitosan (CH) were combined with the excellent thermoplastic and film-forming properties of sodium caseinate (SC) to prepare SC/CH film-forming solutions and films. The antimicrobial effectiveness of SC, CH, and SC/CH coatings on the native microfloras of cheese, salami, and carrots was evaluated.

Essential oils as biopreservatives: different methods for the technological application in lettuce leaves.

Investigations were carried out to assess the efficiency of 3 essential oils, clove, tea tree, and rosemary, as natural preservatives during the postharvest of lettuce leaves. The effect of different concentration (1 and 0.5 MIC) of plant essential oils applied in 3 forms (spray, immersion, and capsules) was studied on lettuce leaves.

Isolation and identification of Bacillus spp. and related genera from different starchy foods.

Unlabelled: Samples of butternut squash, potatoes, rice, and wheat flour were analyzed. Bacillus spp. and related species belonging to Paenibacillus and Brevibacillus genera were found in 96% of the samples.