Dominique Pallet

Changes in antioxidant activity during the ripening of jujube (Ziziphus mauritiana Lamk)

Phenolic compounds from jujube fruits and related antioxidant activities were investigated during the ripening stages. Three different antioxidant assays, including ORAC, FRAP and DPPH, were monitored on crude jujube extract (CJE). Jujube fruits were additionally fractionated into three selective fractions F1, F2, and F3. However, only the FRAP assay gave the relative antioxidant activity for the three fractions. Furthermore, HPLC-ESI-MSMS (Q-Tof) and GC-MS were used to identify the compounds in each purified fraction. Using FRAP, F1 mainly composed of lipids, exhibited the lowest antioxidant activity (≈0.080±0.015mmol trolox/100g, p<0.05). F2, rich in flavanols and flavonols, displayed 50-fold higher activity (4.27±0.11mmol trolox/100g). Remarkably, F3 with an elevated content of condensed tannins (polymeric proanthodelphinidins), exhibited the highest antioxidant activity (25.4±0.35mmol trolox/100g). The presented results showed that the phenolic profiles of the fruits were influenced by their developmental stage. Furthermore, during ripening, the antioxidant activity may be more impacted by the flavanols and condensed tannins. The purified condensed tannins of jujube fruits may be used as natural antioxidant extracts.

Effect of physiological harvest stages on the composition of bioactive compounds in Cavendish bananas

The combined influence of maturation, ripening, and climate on the profile of bioactive compounds was studied in banana (Musa acuminata, AAA, Cavendish, cv. Grande Naine). Their bioactive compounds were determined by the Folin-Ciocalteu assay and high-performance thin layer chromatographic (HPTLC) method. The polyphenol content of bananas harvested after 400 degree days remained unchanged during ripening, while bananas harvested after 600 and 900 degree days exhibited a significant polyphenol increase. Although dopamine was the polyphenol with the highest concentration in banana peels during the green developmental stage and ripening, its kinetics differed from the total polyphenol profile. Our results showed that this matrix of choice (maturation, ripening, and climate) may allow selection of the banana (M. acuminata, AAA, Cavendish, cv. Grande Naine) status that will produce optimal concentrations of identified compounds with human health relevance.

Processing and quality attributes of gowe: a malted and fermented cereal- based beverage from Benin

Gowe is a sweetish paste of malted, fermented, and cooked sorghum and/or maize flour, consumed in its pure state, but preferentially as a beverage after homogenizing with water, sugar, milk, and ice. A survey was carried out at different localities in the traditional gowe producing areas to investigate the diversity of the processing techniques, consumers’ characteristics, and the quality attributes. Producers and sellers were women exclusively while consumers cut across all classes of age, socio-cultural groups, and educational levels. Gowe varied in cereal and processing techniques, with maize and sorghum being used either singly or in combination (maize/sorghum ratio varying from 1 to 3) through four processes. Apart from the alternative process which leaves out the malting step, gowe processing techniques aim at producing sweetish and acidic tasting products through malting, saccharification, and fermentation. A principal component analysis plot of quality criteria of gowe indicated that the preferenc...

Cross-cultural acceptance of a traditional yoghurt-like product made from fermented cereal.

BACKGROUND Akpan is a traditional ready-to-drink fermented yoghurt-like cereal beverage consumed in urban and rural areas in Benin. With the aim of adapting the product to new local and export markets, this work maps African and European consumer preferences for different types of Akpan. RESULTS A sensory profile of Akpan was created and consumer tests were conducted with 103 consumers of African origin and 74 consumers of European origin. Consumer acceptance was significantly correlated with fermented odour (r = -0.94) and milky taste (r = 0.92-0.97) attributes. Cluster analysis revealed different behaviour by African and European consumers with respect to acceptability of Akpan; European consumers did not like the sour taste and African consumers liked an intense sweet milky taste. CONCLUSION This study provides information on how Akpan, and other fermented yoghurt-type cereal products, could be adapted to African and European consumer preferences.

Consumer acceptance and sensory profiling of reengineered kitoza products.

Kitoza refers to a traditional way of preparing beef and pork in Madagascar. However, in order to improve some drawbacks previous identified, the product was submitted to a reengineering process. The acceptance and sensory profiling of improved Kitoza products among Portuguese consumers was investigated. A local smoked loin sausage was selected as basis for comparison. Firstly, a Focus Group study was performed to identify sensory descriptors for Kitoza products and explore product perception. Subsequently, a Flash Profile and a consumer sensory acceptance study were conducted. Flash Profiles results showed that beef- and pork-based Kitoza products investigated differed considerably in all sensory dimensions. The Portuguese sausage was characterized as having a more intense and lasting after taste, as well as displaying a higher degree of (meat) doneness. The acceptance study yielded higher overall liking ratings for pork- than for beef-based Kitoza, although the Portuguese sausage remained the most appreciated product.

Production, consumption, and quality attributes of Akpan - a yoghurt-like cereal product from West Africa

Akpan is a high-potential, traditional yoghurt-like product made from fermented cereal starch, and consumed as a thirst-quenching beverage in Benin. This study investigated the characteristics of consumers, the traditional processing techniques and constraints, and the quality attributes of the product in order to find out the best options for possible industrial development. For this purpose, a survey was carried out in different municipalities using a questionnaire administered to stakeholders. While the production and commercialization of Akpan are undertaken exclusively by women, consumption cuts across all classes of people, with consumers in a wide range of socio-cultural groups, ages, and educational levels. Four types of Akpan were encountered, varying in their raw materials and processing technologies. Maize and sorghum were used either singly or in combination through submerged or solid-state fermentation processes. Among the product types, Akpan from maize ogi was the most preferred, mainly because of its long-established history, white colour, sour taste, and pronounced ogi aroma.

Kenkey production, vending, and consumption practices in Ghana

A survey was conducted to study production, vending, and consumption of kenkey, a sour dumpling in Ghana. Information was obtained on the socio-cultural profile of the actors, processing technologies, practices which adversely affected product quality, shelf life, and quality attributes important to consumers. Kenkey production and retailing was the domain of women, and carried out mainly as a family business in home-based operations. Three types of kenkey were encountered: Ga-, Fanti-, and nsiho-kenkey. Production was dominated by the Ga and Fanti socio-cultural groups but consumption cut across all socio-cultural groups. The majority of producers processed 10–100 kg of maize per week but frequency of production varied from 1 to 10 times in a week. Unit operations in kenkey production were labour intensive and manually carried out apart from milling. The texture of kenkey was more critical to most consumers than taste and depended on a procedure called aflatalization yielding a product with a semi-sticky...

Processed Z. Mauritiana Lamk in the Formula of High Nutritional Value Cake

The nutritional value of jujube fruits Ziziphus mauritiana Lamk was processed through an optimized traditional cake procedure. The characteristics of jujube fruit polysaccharides from an accession known as P3 were determined for each of the 5 ripening stages. Therefore, the content of the Alcohol Insoluble Materials, Water Soluble Polysaccharide and Galacturonic Acid was determined at each ripening stage. The degree of methylation (DM) of jujube pectins was less than 50% therefore was classified as low methoxylated pectin (LM). Using the 3rd and the 5th ripening stage, the impact of the drying and cooking was evaluated on selected nutritional characteristics, including vitamin C, total phenolics content and antioxidant capacity. Remarkably, using the fruits from the 3rd stage, the drying process decreased the vitamin C content (74.5%, p<0.05) whereas an increase of 20% (p<0.05) was observed for the cake. Interestingly, the antioxidant activity was unchanged during the drying process. In contrast, after the cooking process the phenolics content and the antioxidant capacity had both increased, by 64% and 30% (p<0.05) respectively. Overall, our results indicated that stage 3 fruits would exhibit higher nutritional qualities than stage 5 fruits. We strongly recommend stage 3 fruits of accession P3 for food applications, including jujube cake processing.

Sensory Profile and Consumer Acceptability of Ziziphus mauritiana and Processing Product in Savannah Region of Cameroon

Aim: Ziziphus mauritiana is an endemic fruit spread in the savannah region of Cameroon. The fruit, locally called Jaabi, is harvested dry and consumed as such or processed into a local cake named Yaabande, using three baking techniques (sun drying, steam baking and stifle baking). The aim of the study is to characterize the sensory profile and consumer acceptability of the fruit and its processed product, in order to evaluate the determinant of their quality attributes as influenced by ecotype, origin and processing method. Place of Study: The study was carried out in the Department of Food Science and Nutrition, University of Ngaoundere, Cameroon. Methodology: Physico-chemical analysis, sensory profile by a semi trained panel, and consumer acceptability of the fruits and their processed products were undergone through collection of two ecotypes of the fruit (Jaabi Dakamji and Jaabi Lammuji) from four areas (Garoua, Mora, Maroua and Mokolo). African and non African consumers were used for the consumer tests. Results: Sensory analysis differentiated the fruits by ecotype and origin, with the Dakamji ecotype appearing more homogeneous whatever the origin. The processed cakes differed mainly by their texture, depending on the baking method, with chewing texture for sun processed method, while samples from steam and stifle baking were more firm in mouth. Meanwhile, all samples were acceptable at comparable level corresponding to pleasant character, the sweet taste constituting the main criteria for consuming the products, both for African and non African consumers. In this respect Dakamji ecotype was sweeter, due to its higher sugar content, while the sweetness of Lammuji ecotype was lowered by its acid content. Conclusion: Jaabi and Yaabande samples are globally acceptable by consumers, whatever the origin and the variety. Development of products emphasising the original taste of Jaabi and standardisation of processing techniques appear as some main aspects of the market development of the fruit.

Cashew apple extract inhibition of fat storage and insulin resistance in the diet-induced obesity mouse model.

The cashew apple is an unvalued by-product from the cashew nut industry, of which millions of tonnes are simply discarded globally. Interestingly, however, cashew apple nutrients may have beneficial effects for health even if these are still poorly described. The present study was designed to evaluate the effect of a hydro-alcoholic extract of cashew apple (cashew apple extract; CAE; Cashewin™) on obesity and diabetes, in two experimental designs using the diet-induced obesity (DIO) mouse model. First, in the preventive design, mice were treated orally with the CAE at the dose of 200 mg/kg body weight from the first day under a high-fat diet (HFD) and during 8 weeks thereafter. Second, in the curative design, the animals were first maintained under the HFD for 4 weeks and then treated with the CAE for a further 4 weeks under the same regimen. For both experimental designs, body weight, peri-epididymal adipose tissue, liver weight, food consumption, glycaemia, insulinaemia and insulin resistance were assessed. In both designs, the CAE significantly reduced body-weight gain and fat storage in both the peri-epididymal adipose tissue and the liver for mice under the HFD. This was achieved without modifying their energy consumption. Furthermore, glycaemia, insulinaemia and insulin resistance (homeostasis model assessment-insulin resistance) of the DIO mice were significantly lowered compared with the control group. Thus, a well-designed hydro-alcoholic extract of cashew apple could provide an attractive nutritional food ingredient to help support the management of body weight and associated metabolic parameters such as blood glucose and insulin levels.