Effect of alkali treatment of lower concentrations on the structure and tensile properties of Pakistan’s coarse cotton fibre

Abstract

Cotton fibres of high Micronaire values are known to have inferior spinning performance. Either reduction of fibres’ fineness or increase in tensile strength is generally expected to improve the spinnability of fibres. In this piece of research, the effects of alkali treatment at lower concentrations (0.75–2.25M) and higher temperatures (70–100?°C) on the cross-section of cotton fibre and on the tensile strength have been investigated. Observations were made using scanning electron microscopy (SEM) and single fibre tensile strength testing. It was found that the roundness of the fibre cross section was improved and the tensile strength of the fibres also increased after treatment with alkali at lower concentration (0.75?M) and relatively lower temperature (70?°C). It is proposed that such changes occurred due to possible cellulose dissolution/transformations. It was thus concluded that the alkali treatment of cotton fibres at lower concentrations (0.75?M) and 70?°C for a shorter period of time (45 mins) could lead to improvement in tensile strength and roundness of fibre cross-section, thereby improving micronaire.     

Dark vs. light drinks: The influence of visual appearance on the consumer’s experience of beer

We report evidence concerning how the visual appearance of a drink (dark vs. light pale/amber beer) can influence the consumer’s tasting experience. Two experiments were designed to study the effect of visual appearance on people’s hedonic and sensory judgments of beer. Importantly, the beers were indistinguishable in terms of their flavor when tasted in the absence of visual cues.Participants rated the same beer (pale or dark, depending in which group they were assigned) under blind conditions as having more body than when tasted under sighted condition (regardless of whether it was pale or dark; see Experiment 1).When the participants evaluated the expectations and tasting experience of the two different beers under sighted conditions (pale vs. dark), after tasting, those who preferred pale beers, rated the darker beer as tasting sweeter than those who usually prefer other types of beers, such as dark ones (see Experiment 2). Prior tasting, when asked which beer they thought was the most expensive, the majority of the participants chose the darker beer. Furthermore, after tasting both beers, participants reported being willing to pay up to 6% more on average for the darker beer as compared to the pale one.     

The influence of manufacturing and drying conditions on the survival and toxinogenesis of Staphylococcus aureus in two Spanish dry sausages (chorizo and salchichón)

The effects of formulation, starter culture and fermentation temperature on growth and synthesis of toxin A (SEA) and TNase by Staphylococcus aureus during fermentation and drying of Spanish chorizo were investigated. Inhibitory factors able to inhibit SEA synthesis in culture media were unable to prevent SEA production in chorizo fermented at 20 and 30°C, though a lower temperature and starter culture SP318 (Lactobacillus sake, Pediococcus pentosaceous and Staphylococcus xylosus) decreased staphylococcal growth and SEA formation. Reduction and even disappearance of the SEA during ripening was observed. In most batches, TNase was a reliable indicator of staphylococcal growth and SEA production. Dextrose added to the salchichón formulation repressed S. aureus growth during drying. Lactobacillus curvatus in combination with dextrose was an effective anti-staphylococcal agent during fermentation.     

Consumers’ acceptance of recycled water in meat products: The influence of tasting,attitudes and values on hedonic and emotional reactions

Community opposition to potable recycled water may extend to recycled water in food production. Past research on recycled potable water indicates that the closer the risk of personal contact or ingestion, the less acceptable it is. Despite purification and expert assurances, emotional responses, including disgust, may present as major psychological barriers to the environmental and commercial benefit of recycled water use in food production. Consumers (n = 101) were presented with meat products purported to be processed or containing recycled water (3 levels of proximity to ingestion) along with a control product (containing tap water). Hedonic and 18 emotional responses were elicited. Validated survey instruments were used to measure world views (values), beliefs supportive of environmental actions and food technology neophobia seeking to explain variation in hedonic and emotional responses. Surprisingly, consumers were found to be generally accepting and willing to try foods containing or in close proximity to recycled water when that water was collected, treated and returned to drinking water standards within the factory. All hypotheses pertaining to associated values, beliefs and neophobia were rejected. The study suggests that recycling water within a food factory, when supported by a credible and trustworthy source of information, is likely to be met with positive emotional and affective responses. Using a broad range of affective and emotional responses was useful in understanding acceptance of foods that may be associated with perceived risk.     

Impact of the industrial freezing process on selected vegetables — Part I. Structure,texture and antioxidant capacity

In this work, the impact of the industrial freezing process on structure, texture and total antioxidant capacity was studied using green asparagus stems, zucchini and green beans. Samples were analysed as raw/uncooked, blanched, raw/boiled and industrially frozen/boiled.A consistent damage of the vegetable tissue was revealed by the histological analysis on vegetables boiled after freezing. The cells appeared to be dehydrated, contracted and separated at different levels depending on the anatomical structure of each vegetable.The initial textural quality was partially retained in all blanched vegetables, and enhanced in cut tested asparagus stems, in relation to the action of phenolic acids at cell wall level. Raw/boiled and industrially frozen/boiled asparagus stems exhibited comparable forces of penetration and cut tests. On the other hand, zucchini, both raw and frozen, completely softened after boiling making the texture measurement impossible. Industrially frozen/boiled green beans showed higher values of cut and penetration forces, probably due to a higher presence of swollen cell walls, in comparison to those raw/boiled.Blanching and boiling significantly increased the ferric reducing antioxidant power values of asparagus stems and green beans compared to uncooked/raw samples, while boiling after the freezing process significantly deprived both vegetables of the initial antioxidant capacity. On the other hand, boiling the frozen zucchini proved to be detrimental to the antioxidant capacity.In conclusion, manufacturers and researchers should join together to develop specific industrial freezing process conditions according to the matrix of each vegetable.     

Consumers’ attitude towards food by-products: the influence of food technology neophobia,education and information

The aim of the present study was to investigate how food technology neophobia level, socio-economic variables and information about novel foods and technologies may affect consumers’ attitude towards uses of food by-products in relation to positive effects on environment and consumers’ health. Results suggested that education and, most of all food technology neophobia and information, can be critical factors in facilitating the widespread adoption of new food technologies. Moreover, positive attitudes towards food by-products were found, even in people characterised by a greater food neophobia and lower education level. These positive attitudes could be considered a starting point for the food industry to design novel recycling strategies of food by-products in the perspective of the circular economy.     

The influence of ante-mortem hypoxia on the physicochemical stability of myofibrillar proteins in the muscle tissue of white shrimp (Litopenaeus vannamei) exposed to multiple freeze–thaw cycles

The influence of ante-mortem hypoxia on physicochemical stability of white shrimp (Litopenaeus vannamei) muscle exposed to multiple freeze?Cthaw (F/T) cycles was evaluated. Results showed 5.7 and 10.8% decrements in water-holding capacity and myofibrillar protein solubility, respectively, for stressed shrimp during the first F/T cycle compared to control. Significant differences (P????0.05) on myosin T _max were found comparing stressed and control fresh shrimp with a 1.4?°C increased on stressed fresh shrimp; however, no differences were found on ??H values. With regard to stressed fresh shrimp actin, T _max increased (P????0.05) 0.8?°C, while ??H decreased (P????0.05) by 0.12 J?g^?1, respectively. Regardless of the results found in fresh shrimp, no differences were found for myosin T _max and ??H between stressed and control during the F/T cycles. SDS-PAGE showed no relevant changes induced by autolysis during the experiment. Histological analysis showed an increase of 257% in blank area of stressed fresh shrimp when comparing to control. Results showed the influence of ante-mortem hypoxia on the stability of fresh shrimp myofibrillar proteins, affecting its physicochemical properties. In contrast, for shrimp exposed to F/T cycles, the hypoxia effect was not relevant.     

Role of precursors on the kinetics of acrylamide formation and elimination under low moisture conditions using a multiresponse approach – Part I: Effect of the type of sugar

The effect of type of sugar on the kinetics of acrylamide formation and elimination reactions was investigated under low moisture conditions using equimolar asparagine–sugar model systems, heated at temperatures between 120 and 200 °C. The monosaccharides glucose and fructose and the disaccharide sucrose were selected to study this effect. A mechanistic model was used as a basis for multiresponse modelling of the different responses measured (acrylamide, glucose, fructose, sucrose, asparagine, aspartic acid and melanoidins). In spite of the higher acrylamide yield per mol initial asparagine for sucrose over fructose to glucose, the kinetic parameters estimated for acrylamide formation revealed that the type of sugar, monosaccharide or disaccharide, had only a limited effect on this reaction. The corresponding activation energy, however, was significantly lower in case the disaccharide sucrose was added. An opposite trend was observed for the acrylamide elimination rate constant, being significantly higher for the system with sucrose, whereas the temperature dependence of this rate constant remained unaffected by the type of sugar available under the reaction conditions considered.     

Probiotic potential of γ-aminobutyric acid (GABA)–producing yeast and its influence on the quality of cheese

Kazakh cheese is a traditional dairy product in Xinjiang, China. To study the function and potential probiotic characteristics of yeast in Kazakh cheese and its contribution to cheese fermentation, we screened the γ-aminobutyric acid (GABA)–producing yeasts Pichia kudriavzevii 1–21, Kluyveromyces marxianus B13–5, Saccharomyces cerevisiae DL6–20, and Kluyveromyces lactis DY1–10. We investigated the potential probiotic properties of these strains and their use in cheese fermentation (cheeses designated CSP, CSM, CSS, and CSI, respectively); a control with no added yeast was designated CS. The results showed that the 4 yeast strains all showed high self-polymerization (2- and 24-h autoaggregation capacity of >80 and 90%, respectively), hydrophobicity (40–92% variation, low hydrophobicity in xylene, but within the range of probiotics), and the ability to survive the gastrointestinal tract (survival rate >75% after simulation), indicating the probiotic ability of the strains in vitro. The GABA production capacity of the CSM cheese increased (to 95.6 mg/100 g), but its protein content did not change significantly, and amino acid degradation was obvious. The GABA production capacity of the CSS cheese decreased (to 450 mg/kg); its protein content declined, and its amino acid content increased. Except for water and protein, we found no obvious differences in most physical and chemical indicators. Kluyveromyces marxianus B13–5 helped to form the desired texture. Multivariate statistical analysis showed that fermentation of the cheese with the 4 yeasts improved the production of esters and alcohols. The CSS cheese had good aroma production performance, because S. cerevisiae DL6–20 produced high concentrations of isoamyl alcohol, hexanoic acid ethyl ester, benzyl alcohol, octanoic acid ethyl ester, 3-hydroxy-2-butanone, and hexanoic acid; the content of 2-methyl-propanoic acid was low. Compared with the CSP cheese, the CSI and CSM cheeses had a fruitier aroma and a milder odor, but the CSI and CSM cheeses had high concentrations of ethyl acetate, butanoic acid, ethyl ester, 3-methyl-1-butanol-acetate, ethyl hexanoate, ethyl octanoate, acetic acid 2-phenylethyl ester, and ethyl lactate; concentrations of 3-methyl-butanoic acid, propanoic acid, acetic acid, and butanoic acid were low. The CSP cheese had stronger acid-producing ability. The order of fragrance production performance was CSS > CSI, CSM > CSP > CS. Research into the fermentation mechanisms of GABA-producing yeast in cheese will provide a theoretical basis for the quality control and industrial production of Kazakh cheese.     

Studies on the physicochemical characteristics of the New Zealand deer’s tail,Cervus elaphus var. scoticus (III)

Food Science and Biotechnology - This study was designed to determine the nutritional profile and functional components of the NZT (New Zealand deer’s tail, Cervus elaphus var. scoticus...     

The effect of the nutri-score label on consumer’s attitudes,taste perception and purchase intention: An experimental pilot study

A large number of studies has emerged on the environmental impacts of diets, with most studies concluding that a diet rich in plant-based foods, that are low in salt, sugar, and fat, and score high in nutritional values, confers both improved health and environmental benefits. Currently, new interventions are being implemented to improve people’s eating behavior, because most people overconsume unhealthy snacks, containing high proportions of salt, sugar and fat. The purpose of the current pilot study was to investigate the effects of the Nutri-Score label on three different snack bars on consumers’ attitudes, taste perception, and purchase intention towards these food products. An experimental study was conducted with a between subject design (food packaging with Nutri-Score label versus without) among 192 participants (M_age 31.7 years, SD 14.3 years; 63% female). Results showed that there were no effects found for the effect of the Nutri- Score label on consumers’ attitudes, taste perception and purchase intention. Bayesian analyses support the conclusion that the null hypothesis is accepted. These findings show that integrating the Nutri-Score label on food packages did not modify cognitive responses of consumers towards these food products. Changing consumption behaviors is challenging and more empirical and theoretical understanding is needed.     

Kinetics and equilibria of tea infusion: Part 7—The effects of salts and of pH on the rate of extraction of caffeine from Kapchorua Pekoe Fannings

The rates of extraction of caffeine from sieved Kapchorua PF (600–710 μm) have been measured at 80°C with a range of aqueous salt and buffer solutions of ionic strength 0·11 mol dm⁻³. The first-order rate constants and the half-times of infusion showed no trend with pH when buffers from pH 3·0 to pH 8·3 were employed. The rate constants decreased on the addition of common salts like NaCl, KCl and CaCl₂ but increased in the presence of electrolytes such as Bu₄NCl that contain large ions. The results cannot be interpreted by changes in osmotic pressure although Donnan effects may be involved. Close parallels were found between the rate constants and the solubilities of caffeine in electrolyte solutions at 25°C. In particular, the values of both properties rise appreciably in the presence of species containing aromatic or other organic rings with which caffeine molecules associate.     

The effects of nanoemulsions based on citrus essential oils (orange,mandarin, grapefruit,and lemon) on the shelf life of rainbow trout (Oncorhynchus mykiss) fillets at 4 ± 2°C

This study investigated the antioxidant and antimicrobial effects of nanoemulsions of orange, grapefruit, mandarin, and lemon essential oils on rainbow trout fillets stored at 4 ± 2°C in refrigerator. The results demonstrated that the shelf life of the rainbow trout fillets was determined as 10 days for the control group, 12 days for the tween 80 (surfactant), 14 days for orange and lemon treatment groups, and 16 days for mandarin and grapefruit groups. Nanoemulsions based on essential oils removed the fishy odor and had a positive effect on organoleptic quality. The use of citrus essential oil-based nanoemulsions decreased the values of biochemical parameters and slowed the growth of bacteria compared to the control group. Among all treatment groups, only the control group exceeded the TVB-N limit value on the 12th day of storage. PV and FFA values in fillets treated with mandarin and grapefruit nanoemulsions developed more slowly during the storage period. In addition, the lowest bacteria counts were found in the mandarin and grapefruit treatment groups. It can be concluded that especially mandarin and grapefruit EOs in all citrus essential oils can be recommended for preparing nanoemulsions in the preservation of rainbow trout fillets.     

Laboratory studies on parasitism of Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) by two species of Trichogramma Westwood (Hymenoptera: Trichogrammatidae) in different grains,and evaluation of traps for their monitoring

The aim of the present study was to evaluate two species of egg parasitoids under laboratory conditions for biological control of the Indian meal moth Plodia interpunctella, an emerging stored product pest in bulk grain. Trichogramma evanescens proved to be a better candidate for biological control compared to T. cacoeciae as it accepted and parasitised a higher percentage of Indian meal moth eggs. Consequently the foraging of T. evanescens was studied in detail. Preferred oviposition sites on individual seeds by P. interpunctella are the germ region and the raphe. Moth eggs were parasitised at both regions. P. interpunctella eggs received higher parasitism at the germ region compared to the raphe. In stored grain and rice, P. interpunctella eggs can be found in the upper 8 cm of the bulk. Foraging parasitoids were shown to enter up to this depth into wheat, oats, and paella and Basmati rice. Wheat and oats were found most suitable for foraging, as larger numbers of T. evanescens were able to reach this depth as compared to the rice varieties. Among different traps, i.e. probe traps, cone traps and wiregauze tubes with adhesive cardboard, cone traps proved best for monitoring T. evanescens. These cone traps as well as the wiregauze tubes were used for the first time to monitor Trichogramma spp. in bulk grain. Cone traps recorded T. evanescens both when placed on the grain surface and in 5 cm depth within the grain irrespective of the release technique of Trichogramma, i.e. release from cardboard cards or sprinkling loose parasitised eggs. The potential for release of Trichogramma spp. within an integrated control strategy for the Indian meal moth in bulk stored grain and rice is discussed.     

The effects of incorporated resveratrol in edible coating based on sodium alginate on the refrigerated trout (Oncorhynchus mykiss) fillets’ sensorial and physicochemical features

Food Science and Biotechnology - The goal of this study was examining the effects of sodium alginate coating (SA) containing resveratrol (R) on enhancement rainbow trout fillets’ shelf-life....     

The influence of storage on aroma, soluble solids, acid and colour of sour cherries (Prunus cerasus L.) cv. Stevnsbær

The present study involved a laboratory scale experiment where the impact of post-harvest storage on the quality of sour cherries (Prunus cerasus L.) cv Stevnsbær was investigated. Cherries were stored for 7 days at temperatures of 2??°C, 10??°C, 20??°C, and 30??°C, and at 20??°C in combination with a 20% CO₂ atmosphere. Cherry quality was assessed by analysis of soluble solids, titrateable acids, anthocyanins and aroma compounds. The content of soluble solids of cherries decreased at storage temperatures above 10??°C. The anthocyanin content of cherries decreased during storage at all temperatures. A decrease, followed by an increase, in titrateable acid was observed for all temperatures except 2??°C. Aroma components were also affected by storage time and temperature. The level of benzaldehyde decreased during storage at higher temperatures, while those of eugenol and vanillin increased at all temperatures. The levels of "off" odour compounds, like acetic acid and fermentation alcohols, increased at higher temperatures during storage. The CO₂-enriched atmosphere (20%?CO₂) did not affect the different quality factors significantly.