Banana Odor Research Articles

First Record of Ceratocystis fimbriata Causing Quick Wilt of Calotropis gigantea in Pakistan.

Calotropis gigantea belongs to the family Asclepiadaceae, native to Asia and commonly known as crown flower. C. gigantea was identified as an important medicinal plant in Asia and also harvested to obtain the fibres from the stem (Ganeshan et al. 2018; Narayanasamy et al. 2020). In April 2021, a quick wilt epidemic of C. gigantea was observed in District Gujranwala (32°05'58.0"N 74°02'38.0"E) Punjab, Pakistan. The wilt symptoms were very severe on mature plants with 60% disease incidence. Affected plants exhibited yellowing and quick wilting of leaves on each branch that eventually spread to the whole plant (Figure 1). Black patches were observed on the stem bark and cross section of infected stem showed black streaks in the xylem. The samples (n=33) were collected from symptomatic plants. Infected tissues were excised into 4-5mm segments, surface disinfested with 1% NaClO and rinsed 3 times with sterilized distilled water. To induce the sporulation of the fungus, the described carrot baiting method of Moller et al., (1968) was used. Single ascoma from carrot baits were picked under a microscope and transferred to malt extract agar (MEA) medium and incubated at 25°C. Purified cultures were obtained by single spore culture method and all the isolates were preserved with 35% glycerol at -80°C. The fungal colony was greyish olive with overripe banana odour. Hyphae were smooth and segmented. The perithecia were globose, black, measuring 190.27 to 257.34 × 186.11 to 243.24 µm, and showed a long black neck (732 to 977.34 µm). Cylindrical conidia (9.46 to 22.97 µm × 2.7 to 5.41 µm), barrel-shaped conidia (6.34 to 7.95× 8.15-10.41 µm) and chlamydospores (7.65-11.38µm×10.17-16.81µm) were observed (Figure 2). The isolates were identified as Ceratocystis fimbriata based on morphology and similar results were reported by Engelbrecht et al. (2005) and Suwandi et al. (2021). Genomic DNA was extracted from all isolates and multi-locus sequence analysis approach was used for molecular identification. The Internal Transcribed Spacers (ITS) region, the Translation Elongation Factor 1-α gene (TEF) and β-tubulin gene (TUB) were amplified using ITS1/4 (White et al. 1990), EF1-728F/ EF1-986R (Carbone et at. 1999) and βt1a/βt1b (Glass and Donaldson, 1995). Based on the BLAST analysis, all isolates were identified as C. fimbriata. The sequences of the representative isolate AK-W17 were submitted to the GenBank, NCBI database with the accession numbers (ITS:MZ711226), (TEF: MZ714595) and (TUB:MZ714596) showing 100% similarity with AF395687(ITS), MG980731(TEF) and AY177227(TUB) accessions of C. fimbriata. Based on Sequences similarity, representative isolate AK-W17 grouped with the isolates which representing C. fimbriata. Pathogenicity test was conducted on healthy C. gigantea seedlings grown in pots. A fungal mycelium plug (4×4mm) from 15 days old culture of AK-W17 was inserted into a slit (5 × 8 mm and made by puncturing the bark surface) in the stem bark, and the artificial wound was covered with wetted tissue paper and secured with Parafilm to maintain humidity, while control treatment was inoculated with only MEA medium plug. The seedlings were incubated under 70% relative humidity (RH) and 28°C in greenhouse. After 24 days, the inoculated seedlings showed 100% wilting identical to the original plant from which they were isolated (Figure 3). The control treatment had no symptoms. The pathogenic fungus was reisolated and identifies as C. fimbriata based on morphological and molecular characterization. C. fimbriata has been also reported to cause wilt disease in Dalbergia sissoo (Harrington et al. 2015) and pomegranate (Alam et al. 2017) in Pakistan. To our knowledge, this is the first report of C. fimbriata to cause C. gigantea quick wilt in Pakistan. C. fimbriata is one of the most aggressive plant pathogens and rapidly spread worldwide, so it is critical to implement appropriate management practices to reduce the fungus attack on plants.

Identification of discriminating chemical compounds in banana species and their odor characterization using GC-MS, statistical, and clustering analysis.

The online version contains supplementary material available at 10.1007/s13197-021-05298-9.

Lipase immobilization on activated and functionalized carbon for the aroma ester synthesis

This study aimed to investigate the effect of functionalized activated carbon (AC) on lipase immobilization and to use the biocatalysts obtained in the synthesis of isoamyl acetate ester (banana odor). Pupunha palm sheaths were used as a precursor material in the synthesis of activated carbon, which was functionalized by the glutaraldehyde method. The effect of the medium pH and temperature on the lipase immobilization capacity in the different matrices was evaluated, as well as the hydrolytic activity of the derivatives obtained. The AC showed 1260 m2 g−1 surface area and average pore diameter accessible to the enzyme (6.60 nm). The functionalization provided a modification of the matrix surface by the insertion of amine-aldehyde groups and a reduction in porosity and surface area (340 m2 g−1) when compared to AC. The enzyme immobilized on both supports showed specific activity greater than 0.450 U/mg in the best immobilization conditions (pH 5.0 and 30 °C). The immobilized enzyme was used in the esterification reaction, using acetic acid and isoamyl alcohol as a substrate, reaching conversions around 93% and 91% for the enzyme immobilized in the activated and functionalized carbons, respectively, for a reaction time of 180 min. Operational stability showed promising results for both biocatalysts, with no significant reduction in the catalytic activity for ester synthesis during the 5 cycles of reuse studied.

Appetitive and aversive social learning with living and dead conspecifics in crickets

Many animals acquire biologically important information from conspecifics. Social learning has been demonstrated in many animals, but there are few experimental paradigms that are suitable for detailed analysis of its associative processes. We established procedures for appetitive and aversive social learning with living and dead conspecifics in well-controlled stimulus arrangements in crickets, Gryllus bimaculatus. A thirsty demonstrator cricket was released in a demonstrator room and allowed to visit two drinking apparatuses that contained water or saltwater and emitted apple or banana odour, and a thirsty learner was allowed to observe the demonstrator room through a net. In the post-training test, the learner preferred the odour of the water-containing apparatus at which the demonstrator stayed. When a dead cricket was placed on one of the two apparatuses, the learner avoided the odour of that apparatus. Further experiments suggested that a living conspecific can be recognized by either visual or olfactory cues for appetitive social learning, whereas olfactory cues are needed to recognize a dead conspecific for aversive social learning, and that different associative processes underlie social learning with living and dead conspecifics. The experimental paradigms described here will pave the way for detailed research on the neural basis of social learning.

Transgenerational inheritance of learned preferences for novel host plant odors in Bicyclus anynana butterflies.

Many phytophagous insects have strong preferences for their host plants, which they recognize via odors, making it unclear how novel host preferences develop in the course of insect diversification. Insects may learn to prefer new host plants via exposure to their odors and pass this learned preference to their offspring. We tested this hypothesis by examining larval odor preferences before and after feeding them with leaves coated with control and novel odors and by examining odor preferences again in their offspring. Larvae of the parental generation developed a preference for two of these odors over their development. These odor preferences were also transmitted to the next generation. Offspring of butterflies fed on these new odors chose these odors more often than offspring of butterflies fed on control leaves. In addition, offspring of butterflies fed on banana odors had a significant naïve preference for the banana odors in contrast to the naïve preference for control leaves shown by individuals of the parental generation. Thus, butterflies can learn to prefer novel host plant odors via exposure to them during larval development and transmit these learned preferences to their offspring. This ability potentially facilitates shifts in host plant use over the course of insect diversification.

Tracing of Chemical Components of Odor in Peels and Flesh from Ripe Banana on a Daily Basis Using GC-MS Characterization and Statistical Analysis for Quality Monitoring During Storage

A promising research to evaluate the quality of ripe banana during storage period by analyzing the variability of the volatile chemical components in odor from peels and flesh based on solid-phase microextraction-GC-MS characterization and statistical analysis has been discussed. A rapid increase of ethanol concentration in peels and flesh contributes to rotting of the banana. Specifically, occurrence of some compounds, including 1,2-dimethoxybenzene, 3,4-dimethoxybenzaldehyde, and isoeugenol, is an important feature of banana rotting. The decrease of 3-hydroxy-4-methoxybenzaldehyde concentration signifies a weakening of antiseptic, bactericidal, fungicidal, and antioxidant properties of banana. Besides, the principal component analysis (PCA) has been implemented in the discrimination of banana odor at different days of storage.

Changes of aroma components of pineapple wine during fermentation with ADT strain

In order to analyze the changes of volatile organic compounds produced by pineapple juice under the action of ADT yeast, the fermented wine was analyzed by headspace solid-phase microextraction gas chromatography-mass spectrometry. The results showed that a total of 37 volatile compounds were detected by GC-MS in the wine fermented, including 24 kinds of esters, 8 kinds of alcohols and 5 kinds of acids, among which decanoic acid, ethyl ester, hexadecanoic acid, ethyl ester, acetic acid, 2-phenylethyl ester, 3-methylbutyl ester, phenylethyl alcohol and octanoic acid, which are the main flavors of pineapple wine, are produced in the fermentation process and are always present. Octanoic acid, ethyl ester, 1-Butanol, acetic acid, 2-phenylethyl ester, hexanoic acid, ethyl ester, acetic acid, 2-methylpropyl ester and decanoic acid and ethyl ester have a significant increase in the fermentation process. Among them, 1-Butanol, 3-(Methylthio) propyl acetate has a pleasant banana odor, 8 kinds of alcohols were detected, and phenylethyl alcohol was the main alcohol in the fermentation process, has a pleasant jasmine and rose aroma. A total of six acids were detected, octanoic acid and hexanoic acid content are higher in the fermentation.

Odor\u2013color associations differ with verbal descriptors for odors: A comparison of three linguistically diverse groups

People appear to have systematic associations between odors and colors. Previous research has emphasized the perceptual nature of these associations, but little attention has been paid to what role language might play. It is possible odor–color associations arise through a process of labeling; that is, participants select a descriptor for an odor and then choose a color accordingly (e.g., banana odor → “banana” label → yellow). If correct, this would predict odor–color associations would differ as odor descriptions differ. We compared speakers of Dutch (who overwhelmingly describe odors by referring to the source; e.g., smells like banana) with speakers of Maniq and Thai (who also describe odors with dedicated, abstract smell vocabulary; e.g., musty), and tested whether the type of descriptor mattered for odor–color associations. Participants were asked to select a color that they associated with an odor on two separate occasions (to test for consistency), and finally to label the odors. We found the hunter-gatherer Maniq showed few, if any, consistent or accurate odor–color associations. More importantly, we found the types of descriptors used to name the smells were related to the odor–color associations. When people used abstract smell terms to describe odors, they were less likely to choose a color match, but when they described an odor with a source-based term, their color choices more accurately reflected the odor source, particularly when the odor source was named correctly (e.g., banana odor → yellow). This suggests language is an important factor in odor–color cross-modal associations.

Does odor and taste identification change during hyperemesis gravidarum?

To investigate a difference in odor and taste identification among pregnant women with hyperemesis gravidarum, those with healthy pregnancy and non-pregnant women. This prospective, controlled study included 33 pregnant women with hyperemesis gravidarum, 33 healthy pregnant and 26 non-pregnant women. For all participants, rhinological examinations were performed. Odor and taste identification were performed by holding Sniffin' Sticks test battery (Burghart, Wedel, Germany) in all participants. There was a statistically significant difference in results of odor identification tests among the groups (p=0.031). Rose odor was selected as the most pleasant odor by the hyperemesis gravidarum group, 32 (96.9%). Orange odor was selected as the most pleasant odor by the healthy pregnant women, 33 (100%) whereas the banana odor was selected as the most pleasant odor by the healthy non-pregnant women, 10 (38.4%). In taste identification tests, there was a significant difference in total taste scores among the groups (p=0.003). It is obvious that there is a need to evaluate odor thresholds and other parameters by detailed studies on odor perception in the context of hyperemesis gravidarum.

Volatile and non-volatile compounds as odour and aroma predictors in dessert banana (Musa spp.)

To be able to account for sensory quality earlier in the assessment of a new banana hybrid in a selection scheme, the ability of instrumental parameters to predict the sensory perception of banana odour and aroma was investigated. Thirteen cultivated bananas and four new triploid hybrids were characterized by both sensory profiling and chemical analyses. PLS regression models were built using cultivated bananas, and the quality of predictions was validated using hybrids. Forty-one volatile compounds were detected in banana cultivars by SPME–GC–MS. Major differences were observed in the distribution of volatile compounds among cultivars. 3-methylbutyl esters were the most abundant in the 17 banana cultivars. PLS models were able to predict four odours (‘banana’, ‘fermented’, ‘grassy’, and ‘chemical’) and five aromas (‘banana’, ‘fermented’, ‘chemical’, ‘medicinal’, and ‘pineapple’) with a goodness of fit (R2) between 0.52 and 0.71. Two butanoate esters, 2-methylpropyl butanoate and 3-methylbutyl butanoate, mainly contributed to ‘banana’ odour and aroma. Two other esters, 3-methylbutyl acetate and ethyl 3-methylbutanoate contributed to the ‘fermented’, ‘chemical’, and ‘medicinal’ notes, suggesting that interactions between volatile compounds could lead to differences in the perception of odours and aromas. The ‘grassy’ odour was the only attribute which was negatively associated with volatile compounds. Total organic acids enhanced the ‘pineapple’ aroma, whereas it reduced the perception of the ‘banana’ aroma, suggesting interactions between volatile and non-volatile compounds or cognitive associations between aromas and sourness. In conclusion, PLS models can now be used for high throughput phenotyping to predict odours and aromas in dessert banana.

Sensory-Specific Appetite Is Affected by Actively Smelled Food Odors and Remains Stable Over Time in Normal-Weight Women

Understanding overconsumption starts with knowledge of how separate factors influence our eating behavior. Food cues such as food odors are known for their effect on general appetite and sensory-specific appetite (SSA). Active sniffing rather than passive exposure may induce satiation over time. The objective of this study was to investigate how actively sniffing banana odors affects general appetite, SSA, and subsequent food intake. In a crossover study, 61 women actively smelled cups containing natural banana, artificial banana odor, or water (no odor) for 10 min. Treatment order was randomly assigned as much as possible. General appetite and SSA were monitored by using 100-mm visual analog scales during the 10 min of active sniffing, followed by ad libitum intake of banana milkshake. Results showed that SSA was consistently high (+12 mm) during actively sniffing natural or artificial banana odors, with no decrease in SSA over time. Sniffing both banana odors increased the appetite for banana (+11 mm) and other sweet products (+4 mm), whereas the appetite for savory products decreased by 7 mm (all P < 0.01) compared with no odor. Actively sniffing banana odor did not significantly influence food intake (P = 0.68) or general appetite scores (P = 0.06). In conclusion, SSA scores during active sniffing were identical to the SSA found in a similar study that used passive smelling, suggesting that SSA is independent of the manner of sniffing and exposure time. Moreover, sweet/savory categorization may suggest that food odors communicate information about the nutrient composition of their associated foods. These data clearly show the appetizing effects of food odors.

Comparison of volatile aroma compounds in Dwarf Cavendish banana (Musa spp. AAA) grown under organic or traditional cultivation

SummaryThe aroma profiles of ripened fruit of a Dwarf Cavendish banana cultivar grown under traditional (Tr) or organic (Or) cultivation were studied to determine differences in their volatile organic compounds (VOCs). VOCs were extracted using 100% (v/v) dichloromethane, and analysed using gas chromatography (GC) with flame ionisation detection, or by GC–mass spectrometry. According to a sensory panel analysis, extracts of both types of banana were representative of the typical banana odour. A total of 66 VOCs were identified and quantified in Tr bananas, and 76 in Or bananas. Organic bananas contained qualitatively and quantitatively more VOCs. Of all the aroma compounds detected and measured, esters were present in the highest concentrations, followed by aldehydes. The main esters were: isoamyl acetate, 2-pentanol acetate, isoamyl butanoate, 3-methylbutyl-3-methylbutanoate, and n-butyl acetate. The total concentration of esters in Tr bananas was 28.27 mg kg–1, and in Or bananas was 36.34 mg kg–1. Based on the sensory panel analysis, Or bananas were preferred to Tr bananas produced by traditional cultivation because of their improved aroma, texture, and sweetness. A similar conclusion was obtained by chemical and biochemical analysis. Organic cultivation increased soluble solid contents (SSC), fruit firmness, total sugar (Ts), D-fructose, and sucrose concentrations, showing statistically significant differences (P ≤ 0.05).

Comparison of aroma compounds in Dwarf Cavendish banana (Musa spp. AAA) grown from open-field and protected cultivation area

Aroma profile from ripened fruits of Dwarf Cavendish banana cultivars grown under open-field (OF) and protected area (PA) cultivation was studied in order to determine aroma differences. Aroma compounds were extracted with dichloromethane, and analysed by gas chromatography (GC)-flame ionisation detection and GC–mass spectrometry. According to sensory analysis, the aromatic extract of banana was representative of banana odour. A total of 80 components were identified and quantified in OF-banana and 76 in PA-banana. Open-field banana contained more aroma compounds both qualitatively and quantitatively. Of all aroma compounds measured, esters were present in the highest amounts, followed by aldehydes. The main esters were isoamyl acetate, 2-pentanol acetate and isoamyl butanoate. The total amount of esters in OF-banana was 23.8mg/kg and in PA-banana 20.5mg/kg. Based on the sensory analysis, OF-banana was preferred over bananas produced in protected areas, because of their aroma quality.

Imaging evolutionarily conserved neural networks: Preferential activation of the olfactory system by food-related odor

Rodents routinely forge and rely on hippocampal-dependent spatial memory to guide them to sources of caloric rich food in their environment. Has evolution affected the olfactory system and its connections to the hippocampus and limbic cortex, so rodents have an innate sensitivity to energy rich food and their location? To test this notion, we used functional magnetic resonance imaging in awake rats to observe changes in brain activity in response to four odors: benzaldehyde (almond odor), isoamyl acetate (banana odor), methyl benzoate (rosy odor), and limonene (citrus odor). We chose the almond odor because nuts are high in calories and would be expected to convey greater valance as compared to the other odors. Moreover, the standard food chow is devoid of nuts, so laboratory bred rats would not have any previous exposure to this food. Activation maps derived from computational analysis using a 3D segmented rat MRI atlas were dramatically different between odors. Animals exposed to banana, rosy and citrus odors showed modest activation of the primary olfactory system, hippocampus and limbic cortex. However, animals exposed to almond showed a robust increase in brain activity in the primary olfactory system particularly the main olfactory bulb, anterior olfactory nucleus and tenia tecta. The most significant difference in brain activation between odors was observed in the hippocampus and limbic cortex. These findings show that fMRI can be used to identify neural circuits that have an innate sensitivity to environmental stimuli that may help in an animal's survival.

Hyperoxygenation and Bottle Storage of Chardonnay White Wines: Effects on Color-Related Phenolics, Volatile Composition, and Sensory Characteristics

The effects of hyperoxygenation on Chardonnay white musts and the influence of subsequent storage on the corresponding wines have been evaluated. Attention was focused on the color characteristics, phenolic and volatile composition, and sensorial analysis, not previously reported in conjunction. On the one hand, the hyperoxygenation treatment provoked a significant decrease in the concentration of virtually all phenolic compounds in musts, young wines, and one-year-stored wines. In addition, a higher resistance to browning was observed in stored wines derived from hyperoxygenated musts. Different storage conditions (light and dark) produced significant differences in the 2-S-glutathionylcaftaric acid derivatives amounts. On the other hand, significant differences were observed in the volatile composition of wines due to the hyperoxygenation treatment, such as a decrease in the isoamylic alcohols concentration, acetaldehyde, and β-damascenone, even after storage under different conditions. Finally, Chardonnay white wines derived from hyperoxygenated musts had higher banana odor and lower herbaceous and flowery notes.

Differential influence of the ventral subiculum on dopaminergic responses observed in core and dorsomedial shell subregions of the nucleus accumbens in latent inhibition

It has previously been reported that dopamine (DA) responses observed in the core and dorsomedial shell parts of the nucleus accumbens (Nacc) in latent inhibition (LI) are dependent on the left entorhinal cortex (ENT). The present study was designed to investigate the influence of the left ventral subiculum (SUB) closely linked to the ENT on the DA responses obtained in the Nacc during LI, using an aversive conditioned olfactory paradigm and in vivo voltammetry in freely moving rats. In the first (pre-exposure) session, functional blockade of the left SUB was achieved by local microinjection of tetrodotoxin (TTX). In the second session, rats were aversively conditioned to banana odor, the conditional stimulus (CS). In the retention (test) session the results were as follows: (1) pre-exposed (PE) conditioned animals microinjected with TTX, displayed aversion toward the CS; (2) in the core part of the Nacc, for PE-TTX-conditioned rats as for non-pre-exposed (NPE) conditioned animals, DA levels remained close to the baseline whereas DA variations in both groups were significantly different from the DA increases observed in PE-conditioned rats microinjected with the solvent (phosphate-buffered saline (PBS)); (3) in the shell part of the Nacc, for PE-TTX-conditioned rats, DA variations were close to or above the baseline. They were situated between the rapid DA increases observed in NPE-conditioned animals and the transient DA decreases obtained in PE-PBS-conditioned animals. These findings suggest that, in parallel to the left ENT, the left SUB controls DA LI-related responses in the Nacc. The present data may also offer new insight into the pathophysiology of schizophrenia.

Neonatal functional blockade of the entorhinal cortex results in disruption of accumbal dopaminergic responses observed in latent inhibition paradigm in adult rats

Latent inhibition (LI) has been found to be disrupted in non-treated patients with schizophrenia. Dopaminergic (DAergic) dysfunctioning is generally acknowledged to occur in schizophrenia. Various abnormalities in the entorhinal cortex (ENT) have been described in patients with schizophrenia. Numerous data also suggest that schizophrenia has a neurodevelopmental origin. The present study was designed to test the hypothesis that reversible inactivation of the ENT during neonatal development results in disrupted DA responses characteristic of LI in adult rats. Tetrodotoxin (TTX) was microinjected locally in the left ENT at postnatal day 8 (PND8). DA variations were recorded in the dorsomedial shell and core parts of the nucleus accumbens (Nacc) using in vivo voltammetry in freely-moving grown-up rats in a LI paradigm. In the first session the animals were pre-exposed (PE) to the conditional stimulus (banana odour) alone. In the second they were aversively conditioned to banana odour. In the third (test) session the following results were obtained in PE animals subjected to temporary inactivation of the ENT at PND8: (1) aversive behaviour was observed in TTX-PE conditioned animals; (2) DA variations in the dorsomedial shell and core parts of the Nacc were similar in TTX-PE and non-pre-exposed conditioned rats. These findings strongly suggest that neonatal disconnection of the ENT disrupts LI in adult animals. They may further our understanding of the pathophysiology of schizophrenia.

Olfactory conditioning of proboscis activity in Drosophila melanogaster

Olfactory learning and memory processes in Drosophila have been well investigated with aversive conditioning, but appetitive conditioning has rarely been documented. Here, we report for the first time individual olfactory conditioning of proboscis activity in restrained Drosophila melanogaster. The protocol was adapted from those developed for proboscis extension conditioning in the honeybee Apis mellifera. After establishing a scale of small proboscis movements necessary to characterize responses to olfactory stimulation, we applied Pavlovian conditioning, with five trials consisting of paired presentation of a banana odour and a sucrose reward. Drosophila showed conditioned proboscis activity to the odour, with a twofold increase of percentage of responses after the first trial. No change occurred in flies experiencing unpaired presentations of the stimuli, confirming an associative basis for this form of olfactory learning. The adenylyl cyclase mutant rutabaga did not exhibit learning in this paradigm. This protocol generated at least a short-term memory of 15 min, but no significant associative memory was detected at 1 h. We also showed that learning performance was dependent on food motivation, by comparing flies subjected to different starvation regimes.

Striatal dopaminergic responses observed in latent inhibition are dependent on the hippocampal ventral subicular region

We showed recently that behavioural and striatal dopaminergic (DA) responses obtained in latent inhibition are crucially dependent on the parahippocampal region, the entorhinal cortex. In the present study, we investigated the influence exerted by the hippocampal ventral subicular region (SUB) on the DA responses in the anterior part of the dorsal striatum using in vivo voltammetry in freely moving rats and the same latent inhibition paradigm. To that end, the left SUB was temporarily blocked with tetrodotoxin (TTX) during pre-exposure to a new olfactory stimulus (banana odour). During the second session the animals were aversively conditioned to banana odour. With respect to the results obtained during the test session (third presentation of banana odour), similar changes in behaviour and DA levels were obtained in control and conditioned rats microinjected with the solvent, phosphate-buffered saline (PBS), in the SUB, consistently with a latent inhibition phenomenon. In contrast, after reversible inactivation of the SUB during the pre-exposure session, TTX-pre-exposed conditioned animals displayed aversive behaviour in the test session, and anterior striatal DA variations in these animals differed significantly from those obtained in pre-exposed rats injected locally with PBS. Striatal DA variations obtained in conditioned animals microinjected with TTX were also significantly different from those observed in conditioned non-pre-exposed animals. The present data suggest that, in parallel to the entorhinal cortex, the SUB regulates the latent inhibition-related behavioural and DA responses in the anterior part of the dorsal striatum. These data may provide new insight into the pathophysiology of schizophrenic psychoses.

Optimizing conditions for hot water extraction of banana juice using response surface methodology (RSM)

A response surface methodology (RSM) was used for the determination of optimum extraction temperature and time to produce an acceptable banana juice extract. Banana juice was extracted using hot water extraction method at different extraction temperature (35–95 °C) and time (30–120 min). The effects of the extraction conditions on juice yield, total soluble solids (°Brix), banana odour and taste were studied by employing a second-order central composite design. The coefficient of determination, R 2, for juice yield, total soluble solids (°Brix), banana odour and taste were greater than 0.900. Analysis of the regression coefficients showed that temperature was the most important factor that affected characteristics of the banana juice extract as it exerted a highly significant influence ( p < 0.001) on all the dependent variables. An increase in extraction time and temperature of hot water extraction resulted in an increase in juice yield, total soluble solids, banana odour and taste of the banana extract. Based on surface and contour plots, optimum conditions for hot water extraction of banana juice were 95 °C for 120 min.