Post-harvest conservation of organic strawberries coated with cassava starch and chitosan

The strawberry is as non-climacteric fruit, but has a high post-harvest respiration rate, which leads to a rapid deterioration at room temperature. This study aimed to evaluate the application of biodegradable coating on postharvest conservation of organic strawberries, cv. Camarosa, packed in plastic hinged boxes and stored at 10ºC. The treatments consisted of: a) control; b) 2% cassava starch; c) 1% chitosan; and d) 2% cassava starch + 1% chitosan. Physical and chemical characteristics of fruits were evaluated at 3, 6 and 9 days of storage, and microbiological and sensory analyses were carried out at the end of the storage period. The treatments influenced positively the post-harvest quality of organic strawberries. The coating cassava starch + chitosan provided the best results, with less than 6% of loss in fruit mass, lower counts of yeast and psychrophilic microorganisms and the best appearance according to the sensory analysis.

Leishmanial antigens in the diagnosis of active lesions and ancient scars of American tegumentary leishmaniasis patients

Cutaneous biopsies (n = 94) obtained from 88 patients with American tegumentary leishmaniasis were studied by conventional and immunohistochemical techniques. Specimens were distributed as active lesions of cutaneous leishmaniasis (n = 53) (Group I), cicatricial lesions of cutaneous leishmaniasis (n = 35) (Group II) and suggestive scars of healed mucosal leishmaniasis patients (n = 6) (Group III). In addition, active cutaneous lesions of other etiology (n = 24) (Group C1) and cutaneous scars not related to leishmaniasis (n = 10) (Group C2) were also included in the protocol. Amastigotes in Group I biopsies were detected by routine histopathological exam (30.2%), imprint (28.2%), culture (43.4%), immunofluorescence (41.4%) and immunoperoxidase (58.5%) techniques; and by the five methods together (79.3%). In Group II, 5.7% of cultures were positive. Leishmanial antigen was also seen in the cytoplasm of macrophages and giant cells (cellular pattern), vessel walls (vascular pattern) and dermal nerves (neural pattern). Positive reaction was detected in 49 (92.5%), 20 (57%) and 4 (67%) biopsies of Groups I, II and III, respectively. Antigen persistency in cicatricial tissue may be related to immunoprotection or, on the contrary, to the development of late lesions. We suggest that the cellular, vascular and neural patterns could be applied in the immunodiagnosis of active and cicatricial lesions in which leishmaniasis is suspected.

Analysis of ancient DNA from coprolites: a perspective with random amplified polymorphic DNA-polymerase chain reaction approach

The aim of this work was to determine approaches that would improve the quality of ancient DNA (aDNA) present in coprolites to enhance the possibility of success in retrieving specific sequence targets. We worked with coprolites from South American archaeological sites in Brazil and Chile dating up to 7,000 years ago. Using established protocols for aDNA extraction we obtained samples showing high degradation as usually happens with this kind of material. The reconstructive polymerization pretreatment was essential to overcome the DNA degradation and the serial dilutions helped with to prevent polymerase chain reaction (PCR) inhibitors. Moreover, the random amplified polymorphic DNA-PCR has been shown to be a reliable technique for further experiments to recover specific aDNA sequences.

Enterobius vermicularis: ancient DNA from north and south American human coprolites

A molecular paleoparasitological diagnostic approach was developed for Enterobius vermicularis. Ancient DNA was extracted from 27 coprolites from archaeological sites in Chile and USA. Enzymatic amplification of human mtDNA sequences confirmed the human origin. We designed primers specific to the E. vermicularis 5S ribosomal RNA spacer region and they allowed reproducible polymerase chain reaction identification of ancient material. We suggested that the paleoparasitological microscopic identification could accompany molecular diagnosis, which also opens the possibility of sequence analysis to understand parasite-host evolution.

Diagnosing ancient Diphyllobothriasis from Chinchorro mummies

Diphyllobothrium pacificum has been reported as a human parasite from coprolites and skeletons in Peru and Chile. Our analysis of Chinchorro mummies from Chile provides the oldest evidence of D. pacificum directly associated with human mummies. These mummies date between 4,000 and 5,000 years ago. The basis for our diagnosis is presented. We find that the size of the eggs in the mummies is smaller than other discoveries of D. pacificum. We suggest that this is due to the peculiar circumstances of preservation of parasite eggs within mummies and the release of immature eggs into the intestinal tract as the tapeworms decompose after the death of the host. This information is important to consider when making diagnoses from mummies.

Patterns of tuberculosis in the Americas: how can modern biomedicine inform the ancient past?

Tuberculosis (TB) is an infectious disease that continues to take its toll on human lives. Paleopathological research indicates that it has been a significant cause of death among humans for at least five thousand years. Because of the devastating consequences to human health, social systems, and endangered primate species, TB has been the subject of many and varied research efforts throughout the world, efforts that are amassing an enormous amount of data concerning the causative agent Mycobacterium tuberculosis. Despite sequencing of the M. tuberculosis genome and numerous molecular epidemiological studies, many questions remain regarding the origin, evolution, and future co-evolutionary trajectory of M. tuberculosis and humans. Indeed, the origin of pre-Columbian New World TB has been and remains hotly debated, and resolution of this controversy will likely only come with integration of data and theory from multiple disciplines. In this paper, we discuss the pre-Columbian TB controversy, and then use research from biological and biomedical sciences to help inform paleopathological and archaeological studies of this ubiquitous disease that plagued our ancient forbears.

Ancient medical texts, modern reading problems

The word tradition has a very specific meaning in linguistics: the passing down of a text, which may have been completed or corrected by different copyists at different times, when the concept of authorship was not the same as it is today. When reading an ancient text the word tradition must be in the reader's mind. To discuss one of the problems an ancient text poses to its modern readers, this work deals with one of the first printed medical texts in Portuguese, the Regimento proueytoso contra ha pestenença, and draws a parallel between it and two related texts, A moche profitable treatise against the pestilence, and the Recopilaçam das cousas que conuem guardar se no modo de preseruar à Cidade de Lixboa E os sãos, & curar os que esteuerem enfermos de Peste. The problems which arise out of the textual structure of those books show how difficult is to establish a tradition of another type, the medical tradition. The linguistic study of the innumerable medieval plague treatises may throw light on the continuities and on the disruptions of the so-called hippocratic-galenical medical tradition.

Possible influence of the ENSO phenomenon on the pathoecology of diphyllobothriasis and anisakiasis in ancient Chinchorro populations

Current clinical data show a clear relationship between the zoonosis rates of Diphyllobothrium pacificum and Anisakis caused by the El Niño Southern Oscillations (ENSO) phenomenon along the Chilean coast. These parasites are endemic to the region and have a specific habitat distribution. D. pacificum prefers the warmer waters in the northern coast, while Anisakis prefers the colder waters of Southern Chile. The ENSO phenomenon causes a drastic inversion in the seawater temperatures in this region, modifying both the cool nutrient-rich seawater and the local ecology. This causes a latitudinal shift in marine parasite distribution and prevalence, as well as drastic environmental changes. The abundance of human mummies and archaeological coastal sites in the Atacama Desert provides an excellent model to test the ENSO impact on antiquity. We review the clinical and archaeological literature debating to what extent these parasites affected the health of the Chinchorros, the earliest settlers of this region. We hypothesise the Chinchorro and their descendants were affected by this natural and cyclical ENSO phenomenon and should therefore present fluctuating rates of D. pacificum and Anisakis infestations.

Paleoparasitological report on Ascaris aDNA from an ancient East Asian sample

In this study, Ascaris DNA was extracted and sequenced from a medieval archaeological sample in Korea. While Ascaris eggs were confirmed to be of human origin by archaeological evidence, it was not possible to pinpoint the exact species due to close genetic relationships among them. Despite this shortcoming, this is the first Ascaris ancient DNA (aDNA) report from a medieval Asian country and thus will expand the scope of Ascaris aDNA research.

Studies on protozoa in ancient remains - A Review

Paleoparasitological research has made important contributions to the understanding of parasite evolution and ecology. Although parasitic protozoa exhibit a worldwide distribution, recovering these organisms from an archaeological context is still exceptional and relies on the availability and distribution of evidence, the ecology of infectious diseases and adequate detection techniques. Here, we present a review of the findings related to protozoa in ancient remains, with an emphasis on their geographical distribution in the past and the methodologies used for their retrieval. The development of more sensitive detection methods has increased the number of identified parasitic species, promising interesting insights from research in the future.

Cassava and corn starch in maltodextrin production

Maltodextrin was produced from cassava and corn starch by enzymatic hydrolysis with alpha-amylase. The cassava starch hydrolysis rate was higher than that of corn starches in maltodextrin production with shorter dextrose equivalent (DE). DE values do not show directly the nature of the obtained oligosaccharides. Maltodextrin produced from cassava and corn starch was analysed by high performance liquid chromatography (HPLC), and the analysis showed that maltodextrin production differs according to the source of the starch. This is important in defining the application of the maltodextrin, according to its desired function.

Effect of the radiolitic sterilization in polyethylene/starch blends

Samples of LDPE/modified starch blends 80/20 m/m before and after exposure to gamma rays were examined by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction. The effect of gamma radiation is clearly seen in the samples irradiated at a dose of 25 kGy. The main alteration in the polymeric material after exposure at the radiation range was a decrease in the mechanical properties, alterations in the chemical structure of the blend with an increase in the carbonyl and vinyl indices and the appearance of new crystalline symmetry generating a crystalline domain not existing before in the blend.

Citric acid as multifunctional agent in blowing films of starch/PBAT

Citric acid was used as a compatibilizer in the production of starch and PBAT films plasticized with glycerol and processed by blow extrusion. Films produced were characterized by WVP, mechanical properties, FT-IR-ATR and SEM. WPV ranged from 3.71 to 12.73×10-11 g m-1 s-1 Pa-1, while tensile strength and elongation at break ranged from 1.81 to 7.15 MPa and from 8.61 to 23.63%, respectively. Increasing the citric acid concentration improved WVP and slightly decreased film resistance and elongation. The films micrographs revealed a more homogeneous material with the addition of citric acid. However, the infrared spectra revealed little about cross-linking esterification reaction

Starch/poly (butylene adipate-co-terephthalate)/montmorillonite films produced by blow extrusion

This study aims to prepare biodegradable films from cassava starch, poly (butylene adipate-co-terephthalate) (PBAT), and montmorillonite (MMT) using blow-extrusion process and analyze the effects of different types and concentrations of MMT on the microstructure, physicochemical, and mechanical properties of the resulting films. The films were produced by blending 30% of PBAT with glycerol (17.5%), starch (49.0-52.5%), and four different types of montmorillonite (Cloisite® Na+, 10A, 15A, and 30B) at two different concentrations (1.75% and 3.5%). All the films prepared in this study showed an increase in the basal spacing of MMT layers. In particular, the films with 10A and 30B showed the highest increase in intercalation basal spacing, suggesting the formation of intercalated composites. The addition of nanoclays decreased the elongation of films. The addition of Cloisite® 10A resulted in films with the lowest WVP values and the highest stability to water adsorption under different RH conditions.