Microbiota of Tayohounta, a fermented baobab flavour food of Benin

The present work provides data on the microbial composition of Tayohounta, a product of natural fermentation of baobab seed kernels. Samples were collected from 3 different small scale producers from Benin at the end of the fermentation process. Microorganisms were enumerated and identified using phenotypic and molecular approaches. Tayohounta was also investigated using culture independent techniques, direct DNA extraction, polymerase chain reaction - denaturing gradient gel electrophoresis (PCR-DGGE) and cloning. Isolated microorganisms were tested for their functionality in baobab seed kernels fermentation. Total viable counts were around 9 log cfu/g representing mainly Bacillus spp., whereas lactic acid bacteria (LAB) (8 log cfu/g), yeasts and moulds represent a smaller part of the total flora in all Tayohounta samples. Sequencing of clones of polymerase chain reaction (PCR) products of bacterial DNA directly extracted from Tayohounta revealed large differences between the products made by different producers. In all products, Bacillus licheniformis, B. pumilus, B. subtilis, B. thermoamylovorans and Lactobacillus fermentum were present. Other microorganisms (B. thuringiensis, Brevibacterium borstelensis, Enterococcus casseliflavus, E. durans, Lb. agilis, Pediococcus pentosaceus, Streptococcus equinus and Weissella confusa) were present occasionally. In experimental pure culture fermentations, B. subtilis showed little effect on pH, but degraded protein and caused a typical pungent smell typical of Tayohounta

Three Traditional Fermented Baobab Foods from Benin, Mutchayan, Dikouanyouri and Tayohounta: Preparation, Properties and Consumption

Forest food resources contribute significantly to food supply in areas where they grow. Three fermented baobab foods were studied: Dikouanyouri (from seeds, pH = 6.5); Tayohounta (from seed kernels, pH = 7), and Mutchayan (from baobab pulp and sorghum, pH = 4.2). Bacillus spp. (8.5 and 9.5 Log cfu /g) and lactic acid bacteria (8.9 and 8.4 Log cfu /g,) dominate in Dikouanyouri and Tayohounta, respectively. In Mutchayan, lactic acid bacteria (8.1 Log cfu/g) and yeasts (7.2 Log cfu/g) predominated. The arbitrary index of protein cleavage increases from 2.3% (unfermented products) to 13.7% in Dikouanyouri and 21.3% in Tayohounta, indicating significant protein degradation. Mutchayan is the most frequently consumed produc

Quality of pasteurised pineapple juice in the context of the Beninese marketing system

This study is a result of the interdisciplinary project Co-Innovation for Quality in African Food Chains (CoQA). The objective of the research was to improve the quality of pasteurised pineapple juice taking the characteristics of the Beninese pineapple marketing system into account. The specific objectives were to: (i) evaluate the adaptation of Beninese pineapple marketing system to the introduction of the pasteurised pineapple juice business; (ii) assess the extent to which pineapples with physical damage (i.e., of potential less quality) can be used for pineapple juice production; (iii) review the present state-of-the-art on the effect of processing on pineapple juice quality and (iv) evaluate the effect of pasteurisation on the microbiological, physicochemical and nutritional quality of pineapple juice. Chapter 2 of this thesis revealed that wholesalers are the main suppliers to both consumer-merchants and juice manufacturers. However, juice manufacturers’ preferences are different from those of consumer-merchants. More specifically, juice manufacturers prefer large pineapples from 'Kona Sugarloaf' variety and believe that pineapples with physical damage can be used to produce pasteurised pineapple juice. This offers wholesalers the opportunity to sell pineapples that are not demanded by consumer-merchants, but it was found that wholesalers are not engaged in any specific sorting and grading activities to fulfill the wants of the pineapple juice manufacturers. We learned that the reason for the lack of adaptation of the system is caused by the lack of responsiveness of wholesalers due to such factors. The results imply that, in the development context, the adaptation of the marketing system to a development intervention needs to be managed and the effects of interventions need to be considered beyond the primary target group. In other words, complementary marketing interventions should focus on the other actors of the marketing system. As juice manufacturers considered pineapples with physical damage as a possible raw material for pineapple juice production, the possibility of using pineapples with physical damage for pineapple juice production was investigated in chapter 3. Experiments were designed to simulate different types of physical damage and the damaged pineapples were stored for up to 9 days. Physically damaged pineapples stored for up to 9 days at 20 °C showed no adverse effects on the physicochemical characteristics and vitamin C content of fresh pineapple juice (Chapter 3). This suggests that pineapples with those characteristics are suitable for the production of pasteurised juice. Pasteurisation is widely used in juice production. Yet, few studies have investigated the effect of pasteurisation on the quality of pineapple juice (Chapter 4). Due to insufficient proof that pasteurisation has a negative effect on the pineapple juice quality as demonstrated in other juices (Chapter 4), the effect of pasteurisation on the microbiological (mainly yeasts), physicochemical (pH, degree Brix, organic acids, sugars content) and nutritional (vitamin C) quality was investigated in the range of 55 °C to 95 °C. It was found that yeast inactivation in pineapple juice could be described by the Weibull model. The desired 6 log reduction was achieved at 65 °C for 2 min. This result proved that pineapple juice does not need to be pasteurised at a high temperature (85 °C - 20 min) as it is generally applied in Benin and other countries to ensure juice safety. While not expected, vitamin C, the most important nutritional compound in pineapple juice, proved to be stable under the heat treatments investigated in this research. Actually, the degradation rate of vitamin C was below 20 %. Because of this stability, it was not possible to do a kinetic analysis. The physicochemical attributes of pineapple juice, such as pH, degree Brix, organic acid content, were not affected by the pasteurisation treatment. However, at 95 °C, a decrease of sucrose and a simultaneous increase of fructose and glucose contents was noticed, which will probably increase the sweetness of the juice but at the same time favour the Maillard reaction. The fact that HMF was detected in pineapple juice after 30 min at 95 °C, illustrates that the Maillard reaction can affect pineapple juice quality at higher temperatures and longer heat treatments (Chapter 5). Ultimately, pineapple juice should be pasteurised for 2 min at 65 °C to preserve its nutritional (vitamin C) and sensorial quality (colour, taste). Finally, all findings were integrated in chapter 6 and were discussed from an integrative perspective. The thesis has implications for further developing the industry. Currently, the pineapple juice industry is segmented because juice manufacturers differ in many ways. They are living in different locations, have different financial capabilities, different knowledge about juice processing techniques and as a result, they produce pasteurised pineapple juice that is variable in quality. In order to improve their pineapple juice quality and to increase their market access, juice manufacturers can be trained on better pineapple sourcing and pasteurisation techniques. Working more closely together, they can produce products at comparable quality levels using their own equipment. Juice manufacturers who are not willing to collaborate that way can continue to produce and improve their pineapple juice quality by taking the recommendations from this thesis into account.</p

Quality perceptions of stakeholders in Beninese export-oriented shrimp chain

In recent years, the Beninese shrimp sector has faced a ban on export to the European Union due to lack of compliance with food safety standards. The present study aimed at obtaining insight into the factors that determine shrimp quality and safety in Benin. A survey was conducted to investigate the relationships between stakeholders, the conditions under which shrimps are handled at fishing areas and processed at shrimp plants, and the stakeholders' perceptions of quality. A total of 325 fishermen, 128 intermediate traders, 12 collectors, and 3 shrimp processing plant managers were interviewed face to face. The results showed that various specific relations existed between the stakeholders. For example, loyalty was ensured by family relationships, or incentives were provided to ensure a supply of shrimps between stakeholders. Shrimp handling practices during the steps prior to shrimp processing at the plants were not in agreement with the requirements of the European regulations. For example, shrimps were kept at ambient temperature (28 ± 1°C) by 94.1% of fishermen and 60.9% of intermediate traders. Shrimps were also stored in inappropriate holding containers and washed with nonpotable water. Fishermen, intermediate traders, and collectors considered shrimp size and texture their priority quality attributes, whereas plant managers considered shrimp appearance (freshness) and texture their priority quality attributes. This survey demonstrated that the steps prior to shrimp processing at the plants are the critical steps for shrimp quality and safety because of temperature abuse and inappropriate hygienic conditions. There is a need to communicate and provide incentives for the stakeholders in the first part of the chain to give priority to shrimp freshness. Moreover, training in Good Fishing Practices and safe food handling practices and evaluation of compliance with the practices through monitoring will contribute to better shrimp quality and safety management

The Adaptability of Marketing Systems to Interventions in Developing Countries: Evidence from the Pineapple System in Benin

In general marketing theory, marketing systems are assumed to adapt to facilitate further economic development. However, such adaptability may be less obvious in the context of developing countries due to features in the social matrix of these countries. The present study explores adaptation in the Beninese pineapple marketing system in the first ten years after the introduction of the pasteurization process as a development intervention. Qualitative and quantitative insights across a broad spectrum of actors in the pineapple system reveal that adaptability to the intervention has been very slow and virtually absent at an aggregate level. These findings suggest that to make optimal use of the economic development effects of interventions, effects must be considered beyond the primary actor on which they are targeted. This may require complementary marketing interventions at different actors in the system. The marketing systems approach this study adopts seems useful to identify these key actors for complementary interventions

Spoilage evaluation, shelf-life prediction, and potential spoilage organisms of tropical brackish water shrimp (Penaeus notialis) at different storage temperatures

Maintaining the freshness of shrimp is a concern to shrimp stakeholders. To improve shrimp quality management, it is of importance to evaluate shrimp spoilage characteristics. Therefore, microbiological, sensory, and chemical changes of naturally contaminated tropical brackish water shrimp (Penaeus notialis) during storage at 28 °C, 7 °C and 0 °C were assessed. H2S-producing bacteria were the dominant group of microorganisms at 28 °C and 7 °C whereas Pseudomonas spp. were dominant at 0 °C. Total volatile basic nitrogen and trimethylamine correlated well (R2 > 0.90) with the sensory scores. An empirical model to predict the shelf-life of naturally contaminated tropical shrimp as a function of storage temperature was developed. Specific groups of organisms were isolated at the sensory rejection times and assessed for spoilage potential in shrimps of which the endogenous flora was heat inactivated. Isolates capable of producing strong off-odor identified by 16S rRNA sequencing were mainly lactic acid bacteria (LAB) and Enterobacteriaceae at 28 °C or 7 °C and Pseudomonas spp. and LAB at 0 °C. The study contributes to the knowledge about tropical shrimp spoilage and provides a basis for the development of methods and tools to improve shrimp quality management. Keywords: Shrimp quality; Microbiological change; TVBN; Sensory rejection; Shelf-life predictio

The Adaptability of Marketing Systems to Interventions in Developing Countries: Evidence from the Pineapple System in Benin

In general marketing theory, marketing systems are assumed to adapt to facilitate further economic development. However, such adaptability may be less obvious in the context of developing countries due to features in the social matrix of these countries. The present study explores adaptation in the Beninese pineapple marketing system in the first ten years after the introduction of the pasteurization process as a development intervention. Qualitative and quantitative insights across a broad spectrum of actors in the pineapple system reveal that adaptability to the intervention has been very slow and virtually absent at an aggregate level. These findings suggest that to make optimal use of the economic development effects of interventions, effects must be considered beyond the primary actor on which they are targeted. This may require complementary marketing interventions at different actors in the system. The marketing systems approach this study adopts seems useful to identify these key actors for complementary interventions

Prediction of spoilage of tropical shrimp (Penaeus notialis) under dynamic temperature regimes

The spoilage activity of Pseudomonas psychrophila and Carnobacterium maltaromaticum, two tropical shrimp (Penaeus notialis) spoilage organisms, was assessed in cooked shrimps stored at 0 to 28 °C. Microbiological, chemical and sensory analyses were performed during storage. P. psychrophila had a higher growth rate and showed a higher spoilage activity at temperatures from 0 to 15 °C, while at 28 °C, C. maltaromaticum had a higher growth rate. The spoilage activity of P. psychrophila was found to be higher in cooked shrimp than in fresh shrimp. Observed shelf-life data of shrimps stored at constant temperatures were used to validate a previously developed model that predicts tropical shrimp shelf-life at constant storage temperatures. Models predicting the growth of the spoilage organisms as a function of temperature were constructed. The validation of these models under dynamic storage temperatures simulating temperature fluctuation in the shrimp supply chain showed that they can be used to predict the shelf-life of cooked and fresh tropical shrimps

Spoilage evaluation, shelf-life prediction, and potential spoilage organisms of tropical brackish water shrimp (Penaeus notialis) at different storage temperatures

Maintaining the freshness of shrimp is a concern to shrimp stakeholders. To improve shrimp quality management, it is of importance to evaluate shrimp spoilage characteristics. Therefore, microbiological, sensory, and chemical changes of naturally contaminated tropical brackish water shrimp (Penaeus notialis) during storage at 28 °C, 7 °C and 0 °C were assessed. H2S-producing bacteria were the dominant group of microorganisms at 28 °C and 7 °C whereas Pseudomonas spp. were dominant at 0 °C. Total volatile basic nitrogen and trimethylamine correlated well (R2 > 0.90) with the sensory scores. An empirical model to predict the shelf-life of naturally contaminated tropical shrimp as a function of storage temperature was developed. Specific groups of organisms were isolated at the sensory rejection times and assessed for spoilage potential in shrimps of which the endogenous flora was heat inactivated. Isolates capable of producing strong off-odor identified by 16S rRNA sequencing were mainly lactic acid bacteria (LAB) and Enterobacteriaceae at 28 °C or 7 °C and Pseudomonas spp. and LAB at 0 °C. The study contributes to the knowledge about tropical shrimp spoilage and provides a basis for the development of methods and tools to improve shrimp quality management. Keywords: Shrimp quality; Microbiological change; TVBN; Sensory rejection; Shelf-life predictio