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The present study was conducted to investigate the effects of polygalacturonase (PG) treatment on carotenoid absorption upon digestion of HPH-treated combined peach and carrot juice (CJ) with or without the presence of lipids. Results showed that PG treatment reduced median particle diameter (D50) and viscosity of CJ, and increased total carotenoid bioaccessibility by 41%. In the presence of emulsion, the bioaccessibility of carotenoids was higher and it was not significantly affected by PG treatment. Xanthophylls (lutein and zeaxanthin) had higher bioaccessibility than the more lipophilic carotenes (β-carotene and α-carotene); also, uptake in Caco-2 cells and transport of lutein and zeaxanthin were higher than for β-carotene and α-carotene. Individual carotenoids bioaccessibility was negatively correlated with their transport. All together data showed digestion and absorption processes were two independent processes: factors improving carotenoid bioaccessibility did not necessarily affect their bioavailability.

One way to add value to tropical fruit and increase its availability in the global market is to develop new, less perishable, products from fresh fruit. The purpose of this study is to compare the perception of key quality attributes and preferences of dried mango between consumers with different familiarity and health consciousness. This study surveyed respondents from China, Indonesia, and the Netherlands via an adaptive choice‐based conjoint method (n = 483) to evaluate intrinsic quality attributes that influenced consumer preference for dried mango. Consumers in different countries have different texture, taste, and color preferences for dried mango. The most important attribute for the Dutch and Chinese was “free from extra ingredients”, while for Indonesians, it was the texture. Familiarity with dried mango and health consciousness do not influence consumer preference of intrinsic attributes of dried mango. Different preferences of intrinsic attributes of dried mango between countries are related to cultural differences. This study provides useful insights for food manufacturers into the significance of key intrinsic quality attributes in developing dried mango. Practical Application Intrinsic quality parameters of dried mango are not perceived in the same way by every consumer and this is related to cultural differences. Crispy texture is important only for Indonesian consumers, while “free from extra ingredients” is the most important for Dutch and Chinese consumers. This information is relevant when developing dried mango products for the respective markets.

The inhibitory effect of tea polyphenols on starch digestibility can contribute to the control of the glycaemic index of starchy food. In this study, wheat bread and gluten-free bread were co-digested in vitro with different amounts of tea polyphenols. The kinetics of starch digestion and polyphenol bio-accessibility during in vitro digestion were monitored. The results showed that co-digestion of bread with tea polyphenols dose-dependently slowed the starch digestion kinetics and this effect is influenced by the types of polyphenols and the presence of gluten. The presence of gluten lowered the inhibitory efficacy of tannins on starch digestibility to 7.4% and 47.5% when 25 mg of tannins were co-digested with wheat bread and gluten-free bread, respectively. In contrast, the presence of gluten had little impact on the inhibitory efficacy of monomeric polyphenols. This study shows that the release of tea polyphenols in the digestive environment is a promising strategy for controlling the glycaemic index of starchy food and that monomeric and polymeric tea polyphenols differently affect starch digestion according to the presence of gluten.

PurposeAdolescence is a period in which autonomy grows and where children develop into independent and active consumers and a period in which their food choices are also becoming more autonomous. Snacking is known to increase during the period of adolescence and the snack choice of adolescents is often unhealthy. Therefore, the purpose of this study is to know when adolescents perceive a snack as healthy. As healthiness perception could be linked to the perception of naturalness and sustainability of a snack, these are interesting product characteristics to study as well.Design/methodology/approachSemi-structured interviews with 20 adolescents were conducted to characterize their perception of healthiness, naturalness and sustainability. Chocolate snack bars were used as a stimulus product.FindingsAll participants mentioned consuming snacks because they like them. Healthiness was seen as important but was not always a priority in adolescents' snack choices. Naturalness and sustainability were concepts which the adolescents were not aware of or did not perceive as important during snack choice. The adolescents mentioned experiencing natural products to be healthier compared to not natural products. The consequences of the discerned dimensions time, impact and effect of choices were rather limited for this target group.Originality/valueUnderstanding the healthiness, naturalness and sustainability perception of chocolate snack bars by adolescents may help to better understand drivers for adolescents' snack choices.

The present work optimized high-pressure homogenization (HPH) parameters for not-from-concentrate combined peach and carrot juices, based on a two-step comprehensive model using factor analysis and analytic hierarchy process methods. Treating combined juice with pressures over 200 MPa retained more amounts of the bioactive compounds (carotenoids and polyphenols) than non-homogenization. Nutrition-oriented optimization, with higher judgement weight on nutritional properties, and sense-oriented optimization, with higher weight on sensory properties, were set up. Combined juice (250 MPa, 1 pass and 25 °C) had the best quality, based on the nutrition- and sense-oriented models. Back propagation neural network (BPNN) models could predict antioxidant capacities of the combined juice with greater accuracy compared with stepwise linear regression. The relative errors of BPNN prediction model were ≤ 5%.

Purpose In this paper, a conceptual and methodological framework based on empirical evidence derived from the case of the Colombian Cape gooseberry (CG) supply chain is presented. Using this case study, this paper aims to contribute to the extant literature on the internationalization of food supply chains by explicitly considering the alignment of quality attributes and supply chain complexity as key elements to understand the process. Design/methodology/approach This research has been designed to be qualitative, inductive and exploratory, thus involving multiple data gathering methods and tools. More specifically, during the first stage of the empirical analysis, this study has mapped and analysed preferences and perceptions of product quality at both the consumer and supply chain levels. Then, this paper has analysed the degree of alignment and complexity in the supply chain and finally, this study has derived scenarios for the internationalization of the supply chain. Findings The results indicate tensions between supply chain actors related to quality attribute alignment and complexity, which have the potentials to impact the internationalization scenarios of the CG supply chain. Particularly the findings highlight how alignment and complexity of sourcing and product quality attributes can affect supply chain design strategies in different internationalization pathways of a niche food commodity. Research limitations/implications The findings have implications in terms of supply chain design perspectives. In fact, while an approach, which would consider only a transactional or governance perspective would have tackled the problems of misalignment – for example, between farmers and wholesalers or wholesalers and international traders/retailers – it would have ignored the problem of alignment caused at the retailing and consumption stage. In the attempt to internationalize the CG supply chain, farmers, processors and traders are misaligned in relation to the preferences of the targeted final consumers, Dutch/Western European consumers in the case. Practical implications Given the misalignment issues, this paper identifies a step by step approach as the most suitable pathway to design an internationalized supply chain because it allows the CG commodity supply chain to develop the potential market of credence quality-attribute by supporting the health-promoting compounds of the fruit. In this way, the CG supply chain could also progressively scale up and work on solving its misalignment issues by building a coordination structure of the chain, with quality control and logistics likely led by large retailers. Social implications The study indicates that a process of internalization related to a scenario of a “globalized commodity” can only emerge through processes of coordination and integration at the production level, likely led by forms of producers (farmers) associations or a network of producers and traders, leading to strong marketing activities and scale up in terms of volumes. This has profound social implications and calls for rethinking how this study designs the internationalization of niche commodity supply chains. Originality/value Through the application of a mixed methodology approach, in which conceptual, qualitative and quantitative methods have been combined, this paper has been able to identify alternative scenarios to the internationalization and the scale-up of a niche food commodity supply chain, with implications for its design and governance. More specifically in the conceptual model, the different scenarios have been related to the risk of misalignment. The model also identifies alternative pathways of internationalization which may or may not arise according to the way complexity unfolds. In the approach, this study has unpacked complexity by looking into two key dimensions: transactional complexity and quality-attribute complexity.

Color is a main factor in the perception of food product quality. Food surfaces are often not homogenous at micro-, meso-, and macroscopic scales. This matrix can include a variety of colors that are subject to changes during food processing. These different colors can be analyzed to provides more information than the average color. The objective of this study was to compare color analysis techniques on their ability to differentiate samples, quantify heterogeneity, and flexibility. The included techniques are sensory testing, Hunterlab colorimeter, a commercial CVS (IRIS-Alphasoft), and the custom made CVS (Canon-CVS) in analyzing nine different vacuum fried fruits. Sensory testing was a straightforward method and able to describe color heterogeneity. However, the subjectivity of the panelist is a limitation. Hunterlab was easy and accurate to measure homogeneous samples with high differentiation, without the color distribution information. IRIS-Alphasoft was quick and easy for color distribution analysis, however the closed system is the limit. The Canon-CVS protocol was able to assess the color heterogeneity, able to discriminate samples and flexible. As a take home massage, objective color distribution analysis has a potential to unlock the limitation of traditional color analysis by providing more detailed color distribution information which is important with respect to overall product quality.

Citrus juice is widely consumed due to its high nutritional values, desirable taste, and color. The juice color is the key indicator for quality attributes affecting the consumer’s attention. Conventional thermal treatment is the common method in juice processing which adversely affects its nutritional value and appearance. Measuring the color properties of the juice is an intelligent way to control the juice quality and estimating the alteration in chemicals. In this study, the effects of different treatments on the color aspects of citrus juice including L*, a* & b* values, browning index, total color difference, chroma, and hue index were reviewed. New thermal methods such as microwave, ohmic heating, and infrared radiation are used which result in the shortened process come up time (CUT). In addition, non-thermal treatments such as pulsed electric fields, high-pressure processing, high-pressure carbon dioxide, sonication, and ultraviolet are applied to process the juice, which results in better preservation of the nutritional values. These methods are less effective in the inactivation of the enzymes playing a key role in the juices stability. Therefore, a combination of thermal and non-thermal methods is suggested to increase the effectiveness of the process as well as preserving the juice quality.

Inhibition of maltase, sucrase, isomaltase and glucoamylase activity by acarbose, epigallocatechin gallate, epicatechin gallate and four polyphenol-rich tea extract from white, green, oolong, black tea, were investigated by using rat intestinal enzymes and human Caco-2 cells. Regarding rat intestinal enzyme mixture, all four tea extracts were very effective in inhibiting maltase and glucoamylase activity, but only white tea extract inhibited sucrase and isomaltase activity and the inhibition was limited. Mixed-type inhibition on rat maltase activity was observed. Tea extracts in combination with acarbose, produced a synergistic inhibitory effect on rat maltase activity. Caco-2 cells experiments were conducted in Transwells. Green tea extract and epigallocatechin gallate show dose-dependent inhibition on human sucrase activity, but no inhibition on rat sucrase activity. The opposite was observed on maltase activity. The results highlighted the different response in the two investigated model systems and show that tea polyphenols are good inhibitors for α-glucosidase activity.

Background: Heritage food has gained attention and recognition by locals as a cultural identity and by tourists as a new food experience. Two important intrinsic quality attributes of heritage food encompass safety and authenticity. As heritage food dishes are prepared in foodservice establishment, it entails requirements on ensuring safety and authenticity of heritage food. Scope and approach: The study aims to conceptualise heritage food and identify risk factors that may compromise safety and authenticity. A semi-structured literature review was conducted to explain the heritage dimensions and to evaluate multiple food concepts relating to heritage to define the heritage food concept. Furthermore, risk factors were inferred from the literature that could compromise the safety and authenticity of heritage food. Key findings and conclusions: Three main heritage dimensions identified from literature are legacy, people and place. Based on the evaluation against the three heritage dimensions, traditional food was mostly linked to the legacy and place dimensions. Ethnic food was typically related to the dimensions people and legacy, whereas for local food the dimension place was most dominant. Literature showed that all dimensions seem to be relevant for heritage food, but the number of definitions available in the literature is still limited. Therefore, it is not yet clear if all dimensions are equally important. Furthermore, a framework was developed with the identified authenticity risk factors, which originated from literature about ethnic, local and traditional food. The identified safety risk factors are common in the foodservice sector. The framework needs to be further validated through studies with stakeholders in heritage food production.

The increasing interest in heritage food by tourists requires a deeper understanding of its concept. A previous study conceptualised heritage food into three dimensions (i.e. legacy, people and place) and developed a framework describing the main activities in heritage food production, the connection to the identified dimensions and potential authenticity risk factors. This study aims to validate the heritage food concept and the identified authenticity risk factors in the production of heritage food dishes. Semi-structured interviews with culinary professionals of foodservice establishments in Saudi Arabia and Italy were conducted to validate the concept and evaluate the risk factors based on their professional expertise. Data were analysed by thematic content analysis using MAXQDA to infer categories describing the heritage food concept. The results indicated that the previously determined heritage food dimensions were confirmed by professionals. The identified categories ‘inheritance’ and ‘authenticity of the recipe and cooking’ corresponded with legacy, whereas the category ‘locality of ingredients’ linked to place. The category ‘knowledgeable chefs representing their culture’ is related to people. Another category ‘heritage food is subject to cultural and societal influences’ emerged which demonstrates that authenticity is not static but evolves. Most culinary chefs from both countries confirmed the earlier identified authenticity risk factors. Moreover, three new authenticity risk factors arose from the interviews including ‘adaptation to customer preference’, ‘costs of ingredients’, and ‘non-native origin of chef’. Further research is necessary to investigate how these risk factors differ among various types of foodservice establishments.

Background: Food naturalness has been the subject of several recent studies and is a key trend in the food industry. There is currently no comprehensive legal definition of food naturalness, which is a multi-faceted and complex principle composed of many aspects. Naturalness-influencing aspects constituting naturalness of food ingredients are similar to those already investigated for finished food products. Scope and approach: Two research questions are posed in this review: • To what extent are the naturalness criteria for food ingredients set by ISO technical specification 19,657 “Definitions and technical criteria for food ingredients to be considered as natural” in line with the latest trends in consumer studies, reviews and reports on the topic? • What aspects contributing to naturalness of food ingredients are the most present across food ingredients’ categories? The first question is answered through a review of governmental sources and scientific literature related to food naturalness and its evaluation. The second question is addressed through four case studies. Key findings and conclusions: ISO TS 19657 evaluates food ingredients' naturalness and only partially fulfils consumers’ requests. To build up a more comprehensive evaluation system, other aspects e.g. farming practices should be taken into consideration. The case studies presented in this review paper highlighted this need for a more extended basis for naturalness evaluation of food ingredients. A gap between technical and safety need for processing and consumer perception of processing in relation to naturalness emerged.

The kinetics of mass transfer and vitamin C loss in mango during osmotic dehydration (OD) were described by mathematical models. Water loss (WL) and weight reduction (WR) was modelled by Weibull's model, soluble solid gain (SSG) was better described by Peleg's model. Vitamin C loss was described by a multiresponse model incorporating both degradation and leaching processes into the OD-solution. Effects of vacuum impregnation (VI) and pectin methylesterase (PME) addition on the model parameters were evaluated. VI increases SSG indicated by a 55% lower value of k2 in the Peleg model (P < 0.05). PME addition showed no significant effect on the mass transfer kinetics. The major mechanism of vitamin C loss during OD was degradation. The pretreatments have no significant effect on degradation and leaching rate constants of vitamin C. The combination of modelling the mass transfer and vitamin C retention was shown to be valuable in optimizing the OD process design to enhance the health-promoting value of OD mango (sugar content, vitamin C) and processing time.

The effects of pretreatment with vacuum impregnation (VI) and high pressure (HP) and adding pectin methylesterase (PME) with calcium on the quality of osmotic dehydrated mango of different ripeness were investigated. Unripe and ripe ‘Kent’ mango cubes were osmotic dehydrated (OD at 50 °C in 60 °Brix sucrose solution containing 2 g calcium lactate/100 g and 0 or 0.48 mL PME/100 g), preceded either by VI (OD-VI) or HP (OD-HP). Use of unripe mango in OD showed two to five-fold higher soluble solid gain (SSG) compared to ripe mango for all treatments. Unripe mango pretreated with OD-VI showed the lowest water loss (WL) and the highest SSG. OD-HP had a similar but less pronounced effect as OD-VI on WL and SSG. Hue (h*) were generally preserved and color intensity (C*) were maintained or only slightly increased in both ripeness in all treatments. Lightness (L*) was greatly reduced in unripe mango but stable in ripe mango. In general, firmness and work of shear slightly increased when adding PME.

Cape gooseberry is a fruit recognised for having relevant contents of health-promoting compounds. Changes in the content of phytochemicals (ascorbic acid, β-carotene, catechin and epicatechin), hydroxymethylfurfural (HMF) and antioxidant activity of this fruit were studied at various temperatures and times. Ascorbic acid degradation was described by a first order reaction. β-carotene was not degraded and followed an isomerization reaction from 80 °C onwards. Formation of HMF was described with a consecutive zero together with a first order reaction model. The contents of catechin and epicatechin increased at 40 °C. More than three competing reactions did not allow to make kinetic modelling. Antioxidant activity followed fractional first order conversion model. Comparison with kinetics found in other fruits showed that health-promoting compounds of cape gooseberry are relatively more stable to heat treatment. This makes cape gooseberry suitable for the preparation of foods (jam, juices and dehydrated fruit) with relevant health-promoting compounds contents.

Stir-frying is a cooking method, originating from Asia, in which food is fried in small amount of very hot oil. Nowadays in many other parts of the world stir-frying is a very popular method to prepare vegetables, because it is fast and fried vegetables are tasty. However, the retention of phytochemicals like the health-beneficial glucosinolates in Brassica vegetables is less explored for stir-frying in comparison to other cooking methods. This study investigates the retention of glucosinolates in Chinese cabbage (Brassica rapa ssp. pekinensis) and pakchoi (Brassica rapa ssp. chinensis) as affected by stir-frying at various cooking durations and temperatures. Stir-frying experiments were performed at set pan temperatures ranging from 160 to 250 °C for a duration of 1 to 8 min. Results showed that aliphatic glucobrassicanapin is the most abundant glucosinolate identified in fresh Chinese cabbage and pakchoi, contributing for 48 and 63% of the total glucosinolate content, respectively, followed by glucoiberin and gluconapin. Stir-frying retains the glucosinolates even at the highest temperature applied. Such retention is explained by the quick inactivation of the glucosinolate-hydrolytic enzyme myrosinase during the first minutes of frying, and by the thermal stability of the glucosinolates at those temperature/time conditions. Moreover, due to the absence of a separate water phase, leaching losses did not occur, in contrast to what is observed when boiling Brassica vegetables. These results show that stir-frying may be a suitable health-beneficial cooking option that prevents the loss of glucosinolates.

Cape gooseberry is the fruit of the plant Physalis peruviana L. and has gained commercial and scientific interest for its contents of health-promoting compounds. An integral approach to estimate shelf life of cape gooseberry was conducted taking into account physicochemical, microbiological and nutritional changes and consumer acceptance. The experiments were performed for 5 independent harvest times during two years (2014–2015). The conditions of storage were temperatures of 4, 8 and 12 °C and a relative humidity of 80%. Fruit with (Y) and without calyx (N) were packed into polyethylene terephthalate (PET) trays and polypropylene (PP) baskets, respectively. The experiment was conducted for a total of 76 d or shorter when the fruit was spoilt earlier. Fruit with the calyx showed a longer shelf life, while 8 °C was the temperature that gave longer shelf lives irrespective of the calyx presence. The critical quality attribute of shelf life without calyx was fungal growth, which determined consumer acceptance; weight loss was the most critical quality attribute for the fruit with calyx. Studying various quality attributes in an integral way appeared to give a better understanding of the shelf life.

Although the monkey orange (Strychnos spp.) tree fruit is widely distributed in Southern Africa and particularly in Zimbabwe, it is underutilized and little attention has been given to its potential commercialisation due to limited knowledge and information. Most of the fruits and their products are wasted because of limited harvest time, process control and storage conditions, leading to variability in shelf life and sensory quality, thereby impacting nutritional quality. Traditional processing techniques make insufficient use of this food resource within rural communities. This study aimed at identifying the existing bottlenecks by means of a survey among 102 smallholder farming respondents in the wet and dry regions of Zimbabwe. Results revealed that S. cocculoides and S. spinosa were used by 48% of respondents as a functional ingredient in porridge, by 25% in fermented mahewu drink and by 15% of respondents as a non-alcoholic juice. The fruits of S. innocua and S. madagascariensis are preferably processed into dried products. Taste, flavour and colour were the important quality characteristics for all processed products, and constraints to be solved are seed-flesh separation, long processing times, separation of juice and pulp during storage as well as pulp viscosity. Respondents reported monkey orange products to have health benefits for children and immune-compromised people, who, on regular consumption, have reportedly increased weight and resistance to disease. The positive perception about the processed products of Strychnos spp. offer a good opportunity to improve nutrition security by capitalizing on these not-yet-fully-exploited resources, but technological solutions to improve sensory quality and shelf life must be developed.

Key message Overexpression of BoMYB29 gene up-regulates the aliphatic glucosinolate pathway in Brassica oleracea plants increasing the production of the anti-cancer metabolite glucoraphanin, and the toxic and pungent sinigrin. Abstract Isothiocyanates, the bio-active hydrolysis products of glucosinolates, naturally produced by several Brassicaceae species, play an important role in human health and agriculture. This study aims at correlating the content of aliphatic glucosinolates to the expression of genes involved in their synthesis in Brassica oleracea, and perform functional analysis of BoMYB29 gene. To this purpose, three genotypes were used: a sprouting broccoli, a cabbage, and a wild genotype (Winspit), a high glucosinolate containing accession. Winspit showed the highest transcript level of BoMYB28, BoMYB29 and BoAOP2 genes, and BoAOP2 expression was positively correlated with that of the two MYB genes. Further analyses of the aliphatic glucosinolates also showed a positive correlation between the expression of BoAOP2 and the production of sinigrin and gluconapin in Winspit. The Winspit BoMYB29 CDS was cloned and overexpressed in Winspit and in the DH AG1012 line. Overexpressing Winspit plants produced higher quantities of alkenyl glucosinolates, such as sinigrin. Conversely, the DH AG1012 transformants showed a higher production of methylsulphinylalkyl glucosinolates, including glucoraphanin, and, despite an up-regulation of the aliphatic glucosinolate genes, no increase in alkenyl glucosinolates. The latter may be explained by the absence of a functional AOP2 gene in DH AG1012. Nevertheless, an extract of DH AG1012 lines overexpressing BoMYB29 provided a chemoprotective effect on human colon cells. This work exemplifies how the genetic diversity of B. oleracea may be used by breeders to select for higher expression of transcription factors for glucosinolate biosynthesis to improve its natural, health-promoting properties. Electronic supplementary material The online version of this article (10.1007/s11103-019-00890-2) contains supplementary material, which is available to authorized users.

This paper studied the nutritional impact of the use of juice from Strychnos cocculoides (monkey orange) in a maize-based porridge. Monkey orange juice is traditionally used to supplement maize porridge - a staple breakfast cereal especially for vulnerable groups. Monkey orange fruits contain high amounts of micronutrients and phenolic compounds and are widely distributed throughout sub-Saharan Africa. The valuable components can be efficiently extracted by traditional and pectinase maceration techniques. The bioaccessibility of minerals and main phenolic compounds in maize porridge (5 g maize meal) supplemented by monkey orange juice (100 ml) were assessed after in-vitro digestion together with the kinetics of starch degradation. Caffeic and protocatechuic acids exceeded 100%, and chlorogenic acid 81% bioaccessibility after simulated intestinal digestion. Rutin was undetected after the simulated intestinal phase due to precipitation in the pellet. In-vitro bioaccessibility of minerals ranged from 12 to 62% in monkey orange enriched porridge. A 50–70% decrease of starch hydrolysis was observed at the end of the simulated intestinal digestion of monkey orange maize porridge confirming the known potential of phenolic compounds to decrease the glycaemic index of starch-rich foods. Consequently monkey orange juice appeared a suitable ingredient to enrich staple maize porridge thanks to its micronutrients and health benefit potential. Similar relationships of other fruits and starchy foods warrant study as a means to improve the nutritional quality of the diets of malnourished populations.

Background The fruit of Physalis peruviana L ., known as Cape Gooseberry (CG) is a source of a variety of compounds with potential health benefits. Therefore, CG has been subject of scientific and commercial interest. Scope and approach This review paper evaluates changes of such health-promoting compounds and antioxidant activity in CG, based on published literature and from a supply chain perspective, considering pre-harvest, post-harvest, processing (thermal and not thermal) and storage steps to give an insight of contents at consumption stage. Key findings and conclusions CG has vitamin C (20 and 35 mg 100 g −1 FW), β-carotene (up to 2.0 mg.100 g −1 FW), total phenolic compounds TPC (50–250 gallic acid equivalents.100 g −1 FW), phenolic acids (caffeic, gallic, chlorogenic, ferulic and p -cumaric acids), flavonoids (quercetin, rutin, myricetin, kaempferol, catechin and epicatechin) and antioxidant activity. There is not yet evidence of presence of physalins and withanolides in CG as previous review papers have stated. The ripeness stage of CG is a relevant factor affecting the content of many phytochemicals. Vitamin C and β-carotene contents are directly proportional to ripeness stage. The reported data in literature showed a large variation, likely caused by different raw material properties (origin, ripeness stage, growing conditions etc.) and differences in the employed analytical methods. Thermal and non-thermal processing have an effect on the extractability of the phytochemicals but also on the decrease of compounds and antioxidant activity. Relative stability to certain phytochemicals to processing suggest an opportunity to add value to supply chain with processed food containing health-promoting compounds.

BACKGROUND: Kales are often a key ingredient of traditional foods, containing high amounts of indolic glucosinolates (precursors of indole-3-carbinol and ascorbigen), carotenoids and phenolics. The present trend to associate traditional foods crops with health-promoting properties suggested to investigate the degradation kinetic of three Brassica oleracea landraces' phytochemicals subjected to boiling, steaming and stir-frying. RESULTS: Boiling led to substantial losses due to leaching. Glucosinolates followed a second-order degradation kinetic (20% of their initial values after 10min in Nero di Toscana). Phenolic content in leaves+cooking water remained unchanged, whereas their antioxidant capacity was reduced. Carotenoid content increased during the first minutes of boiling. Steaming showed the highest retention of phytochemicals, with often zero-order degradation kinetic, having however a strong effect on colour. Stir-frying produced high losses for all measured compounds; also, β-carotene reduced its content to 10-23% independently of variety. Conversion values for indole-derived compounds ranged from non-detectable to 23.5%. CONCLUSION: Variety strongly affected observed degradation rates because of a different glucosinolate composition and leaf structure. With this research, more information has been gained on the degradation kinetic of B. oleracea landraces' phytochemical compounds upon cooking, highlighting the possibility of improving bioactive component retention.

Monkey orange (Strychnos spp.) is a widely distributed fruit species in Southern Africa commonly consumed by the local population. It has potential to improve the nutritional status of rural populations, being a precious food source in areas with periodic shortages, since it is rich in vitamin C, zinc, and iron. To improve the availability of this food outside its production season, processing and preservation techniques used at household level need upgrading as they are unreliable and their effects on nutritional quality are unknown. Based on this review, we recommend better indigenous fruit production as a sustainable solution to malnutrition in rural areas in transition countries.

Pectin, a major polysaccharide found in the cell walls of higher plants, plays major roles in determining the physical and nutritional properties of fruit- and vegetable-based products. An in-depth understanding of the effects of processing operations on pectin structure and functionality is critical for designing better products. This review, therefore, focuses on the progress made in understanding the effects of processing on pectin structure, further on pectin functionality, consequently on product properties. The effects of processing on pectin structure are highly dependent on the processing conditions. Targeted control of pectin structure by applying various processing operations could enhance textural, rheological, nutritional properties and cloud stability of products. While it seems that optimizing product quality in terms of physical properties is counteracted by optimizing the nutritional properties. Therefore, understanding plant component biosynthesis mechanisms and processing mechanisms could be a major challenge to balance among the quality indicators of processed products.

In this study, the effect of berry polyphenols on starch digestion was tested in vitro both by co-digestion of berry extract with bread or by fortifying bread with berry extract. Results show that the co-digestion of bread with berry extracts significantly reduce the rate and extent of starch digestion. Sixty one percent of starch digestion is inhibited by co-digesting 1 g of raspberry extract with 4 g of the bread. The inhibition obtained by co-digesting berry extracts and bread is much higher than the inhibition obtained by digesting berry-fortified bread. Interactions of polyphenols with matrix reduce polyphenols bio-accessibility, thus reducing the amount of polyphenols available for α-amylase inhibition. The interaction of polyphenols and starch seems also a crucial mechanism for the inhibition of starch digestion. This study shows that the co-ingestion of berry polyphenols with bread is a promising strategy to reduce glycaemic index of starchy food.

Moisture content plays a pivotal role in the kinetic modelling of the quality attributes during thermal processing of foods. Vacuum frying of mango chips, was chosen to demonstrate the applicability of this novel modelling approach that links a dynamic moisture model to models for changes in fat content, texture, and color. Results show that moisture loss is best described by an exponential model with an Ea of 40.0 ± 4.2 and 27.2 ± 2.3 kJ mol−1 for unripe and ripe mango respectively. The dynamic moisture content was linked to the fat content by a Gompertz model, and to the hardness by an exponential model. By using thermodynamic principles, the moisture model predicts the dynamic local product temperature that can be linked to the reaction rates of the consecutive color change reaction models. The integration of these models is a powerful tool in product and process optimization to produce high quality vacuum fried fruit products. Industrial relevance text Food moisture content changes during many thermal processing techniques but it also plays a pivotal role in changes of the quality attributes of foods. Quality change models were developed that integrate changes in the moisture content with changes in quality attributes. These models can be applied to produce a minimal fat content and low moisture content while getting a desired color change and/or to produce a specific texture characteristics. Moisture dependent models for quality changes are powerful tools for optimizing many other products and process.

Vacuum frying of fruits enables frying at lower temperatures compared to atmospheric frying, thereby improving quality attributes of the fried product, such as oil content, texture, retention of nutrients, and color. Producing high-quality vacuum-fried fruit is a challenge, especially because of the high initial water content of fruits that requires long frying times. Factors influencing vacuum-fried fruit quality attributes are the type of equipment, pre-treatments, processing conditions, fruit type, and fruit matrix. Pre-treatments such as hot air, osmotic drying, blanching, freezing, impregnation, anti-browning agents, and hydrocolloid application strongly influence the final quality attributes of the products. The vacuum-frying processing parameters, namely frying time, temperature, and vacuum pressure, have to be adjusted to the fruit characteristics. Tropical fruits have different matrix properties, including physical and chemical, which changed during ripening and influenced vacuum-fried tropical fruit quality. This paper reviews the state of the art of vacuum frying of fruit with a specific focus on the effect of fruit type and matrix on the quality attributes of the fried product.

BACKGROUND: Glucosinolates are a group of phytochemicals that are abundant in cruciferous vegetables and precursors of the potentially chemopreventive isothiocyanates. Isothiocyanates may reduce oxidative stress and inflammation, but little is known regarding the association between glucosinolate intake and risk of type 2 diabetes (T2D). OBJECTIVE: To evaluate the association between the intake of glucosinolates and the incidence of T2D in US men and women. DESIGN: This prospective cohort study investigated 200,907 women and men [71,256 women from the Nurses’ Health Study (NHS; 1984–2012), 88,293 women from the NHS II (1991–2013), and 41,358 men from the Health Professionals Follow-Up Study (1986–2012)] who were free of diabetes, cardiovascular disease, and cancer at baseline. Diet was assessed using validated semiquantitative food frequency questionnaires. Self-reported T2D incidence was confirmed by a supplementary questionnaire. RESULTS: During follow-up in the 3 cohorts, we accumulated 4,303,750 person-years and 16,567 incident cases of T2D. After adjustment for major lifestyle and dietary risk factors for T2D, participants in the highest quintile of total glucosinolate intake had a 19% higher risk (95% CI: 13%, 25%; P(trend)

Chewing disrupts broccoli cells, and myrosinase can effectively hydrolyze the glucosinolate glucoraphanin into the biological active sulforaphane. The influence of chewing time and steaming time on glucoraphanin hydrolysis as well as sulforaphane and sulforaphane nitrile formation in broccoli was studied. To study the effect of chewing time on differently steamed broccoli, broccoli was chewed for 11 s, 22 s, 30 s and 40 s by volunteers. To determine the effect of steaming time, raw and steamed broccoli samples were chewed for 22 s. Glucoraphanin, sulforaphane and sulforaphane nitrile were analyzed in all samples. Longer chewing times of raw, 0.5-min and 1-min steamed broccoli, which contained active myrosinase, lead to a higher hydrolysis. The highest hydrolysis rate of glucoraphanin was found in 0.5-min steamed broccoli (38%) and 2-min steamed samples which contained the highest sulforaphane concentration. This could lead to a recommendation to steam broccoli for a short time before consumption.

cope Optimization of bioavailability of dietary bioactive health-beneficial compounds is as important as increasing their concentration in foods. The aim of this study was to explore the change in bioavailability of isothiocyanates in broccoli sprouts incorporated in protein, fibre and lipid gels. Methods and results Five participants took part in a cross-over study and collected timed urine samples before up to 24-hours after consumption of proteins, dietary fibres and lipids gels containing broccoli spouts powder. Sulforaphane and iberin metabolites were determined in the urine samples. Samples in which sulforaphane and iberin were pre-formed by myrosinase, led to a higher bioavailability of those compounds. Compared to the control broccoli sprout, incorporation of sprouts in gels led to lower bioavailability for pre-formed sulforaphane and iberin (although for sulforaphane the lower bioavailability was not significantly different) whereas, for the gels rich in their precursors, glucoraphanin and glucoiberin, the opposite trend was observed (although not significantly different). Conclusion This explorative study suggests that isothiocyanates bioavailability can be modulated by food structure and composition and further and deeper investigations are needed to develop food products that lead to an optimized isothiocyanates bioavailability. This article is protected by copyright. All rights reserved

Tomato fractions were subjected to pulsed electric fields treatment combined or not with heating. Results showed that pulsed electric fields and heating applied in combination or individually induced permeabilization of cell membranes in the tomato fractions. However, no changes in β-carotene and lycopene bioaccessibility were found upon combined and individual pulsed electric fields and heating, except in the following cases: (i) in tissue, a significant decrease in lycopene bioaccessibility upon combined pulsed electric fields and heating and heating only was observed; (ii) in chromoplasts, both β-carotene and lycopene bioaccessibility significantly decreased upon combined pulsed electric fields and heating and pulsed electric fields only. The reduction in carotenoids bioaccessibility was attributed to modification in chromoplasts membrane and carotenoids-protein complexes. Differences in the effects of pulsed electric fields on bioaccessibility among different tomato fractions were related to tomato structure complexity.

The formation of health‐beneficial isothiocyanates (ITCs) from glucosinolates depends on a wide variety of plant‐intrinsic factors (e.g., concentration of glucosinolates, activity of myrosinase, and specifier proteins) and on a multitude of extrinsic postharvest factors such as the conditions used during industrial processing, domestic preparation, mastication, and digestion. All of these factors contribute to a large variability in the formation of ITCs (and other breakdown products), as well as their intake and absorption upon consumption of Brassica vegetables. This uncertainty in ITC intake and absorption is a barrier for the determination of an optimal Brassica vegetable consumption pattern. In this review, the intrinsic and extrinsic factors that affect the formation, intake, and absorption of ITCs are described according to the most recent findings. The focus of this review includes the hydrolysis reaction mechanisms, the elucidation of the primary factors that play a role in the hydrolysis reaction, the influence of processing and cooking conditions, the effect of chewing, and the roles of the gastric and upper intestinal phases, including the effect of the meal composition (e.g., the effect of other meal compounds present during digestion) on the potential formation of ITCs.

Aims: This study explores the biofumigation effects of glucosinolate (GSL) containing Brassica oleracea plant material on beneficial, non-target soil organisms, and aims to relate those effects to differences in GSL profiles. Methods: Leaf material of purple sprouting broccoli 'Santee', Savoy cabbage 'Wintessa', and the wild B. oleracea accession Winspit was analysed for GSL production and used for biofumigation experiments on the beneficial soil invertebrates, Folsomia candida (springtail) and Eisenia andrei (earthworm) and the soil bacterial community. Results: When mixed into soil, the Winspit plant material exerted the highest toxic effects on beneficial soil invertebrates by reducing survival and reproduction. Total GSL levels varied substantially between genotypes, in particular the aliphatic GSL (AGSL) sinigrin and gluconapin being highly abundant or exclusively present in Winspit. Differences between the genotypes regarding biofumigation effects on the soil microbial community were only observed on a temporal basis with the largest difference in bacterial community structure after 1 week. Conclusions: The high total GSL content in biofumigated soil could explain the toxicity of Winspit for soil invertebrates. These effects are likely to be the results of high AGSL levels in Winspit. The use of wild B. oleracea crops, such as Winspit, for biofumigation practices would need a proper assessment of the overall impact on soil biota before being applied on a wide scale.

Purpose – Domestic preparation practices influence the sensory properties and nutritional composition of food products. Information on the variability in actual domestic preparation practices is needed to assess the influence of applied conditions on the sensory and nutritional quality of food. The collection of such information requires a reliable, valid and practical research method. The paper aims to discuss these issues. Design/methodology/approach – Direct in-home observations, observations in a model-kitchen using cameras, and a self-reporting questionnaire were evaluated for reliability and validity, to study domestic food preparation practices by consumers. Broccoli preparation practices by Dutch consumers were checked by these three methods in this research paper. Findings – All three research methods were found to be test-retest, inter-observer, parallel-form reliable; and face, content and concurrent valid. However, the self-reporting questionnaire is the most practical research method that can be administered on a large number of respondents in a short time to capture the wide variations in preparation practices. Originality/value – Consumers can be assisted on domestic food preparation practices that reach their sensory preferences (e.g. texture, colour) as well as have health benefits on consumption.

The healthiness of a vegetable cannot solely be inferred from the amount of health-promoting compounds in the raw materials. Brassica vegetables, for example, are consumed mostly after processing to improve palatability and to extend the shelf life. However, processing also results to various changes in the content of glucosinolates which intakes are associated with a reduced risk of several cancers. The large variety in cooking practices and processing methods affect the glucosinolate content in the vegetables, particularly due to processes that allow for enzymatic hydrolysis and thermal degradation of glucosinolates, and leaching of the bioactive components. Knowledge on the effect of preparation and processing of Brassica vegetables is important to evaluate the healthiness of the consumed product and to investigate mechanisms to retain high glucosinolate levels at the stage of consumption and to increase the intake of health-protective compounds by the consumer. By using a mechanistic approach, the fate of glucosinolates during different processing and preparation methods and conditions can be explained. Boiling and blanching reduce the glucosinolate content significantly particularly because of the mechanisms of leaching following cell lysis and diffusion, and partly due to thermal and enzymatic degradation. Steaming, microwave processing, and stir frying either retain or only slightly reduce the glucosinolate content due to low degrees of leaching. These methods can enhance the accessibility of glucosinolates from the plant tissue. Fermentation reduces the glucosinolate content considerably, the underlying mechanisms are not yet completely clear, but enzymatic breakdown seems to play an important role. Studying the changes of glucosinolates during processing by a mechanistic approach is shown to be valuable to redesign the processing and to reformulate the product for improving health benefits of these compounds.

Consumption of glucosinolate-rich Brassicales vegetables is associated with a decreased risk of cancer with enzymatic hydrolysis of glucosinolates playing a key role. However, formation of health-promoting isothiocyanates is inhibited by the epithiospecifier protein in favour of nitriles and epithionitriles. Domestic processing conditions, such as changes in pH value, temperature or dilution, might also affect isothiocyanate formation. Therefore, the influences of these three factors were evaluated in accessions of Brassica rapa, Brassica oleracea, and Arabidopsis thaliana. Mathematical modelling was performed to determine optimal isothiocyanate formation conditions and to obtain knowledge on the kinetics of the reactions. At 22 °C and endogenous plant pH, nearly all investigated plants formed nitriles and epithionitriles instead of health-promoting isothiocyanates. Response surface models, however, clearly demonstrated that upon change in pH to domestic acidic (pH 4) or basic pH values (pH 8), isothiocyanate formation considerably increases. While temperature also affects this process, the pH value has the greatest impact. Further, a kinetic model showed that isothiocyanate formation strongly increases due to dilution. Finally, the results show that isothiocyanate intake can be strongly increased by optimizing the conditions of preparation of Brassicales vegetables.

Broccoli is a rich source of the glucosinolate glucoraphanin (GR). After hydrolysis of GR by the endogenous enzyme myrosinase, sulforaphane (SF) or sulforaphane nitrile (SFN) are produced, depending on environmental conditions. How the conversion of GR and bioaccessibility of released breakdown products are affected by steaming (raw, 1 min, 2 min and 3 min steamed) and meal composition (protein or lipid addition) was studied with an in vitro digestion model (mouth, stomach, intestine, but not colonic digestion). The main formation of SF and SFN occurred during in vitro chewing. The contents of GR, SF and SFN did not change after further digestion, as the irreversible inactivated myrosinase under gastric conditions caused no further GR hydrolysis. SF concentrations were up to 10 times higher in raw and 1 min steamed broccoli samples after digestion compared to longer-steamed broccoli. Protein or lipid addition had no influence on the formation and bioaccessibility of SF or SFN.

Background: Glucosinolates (GLSs) are dietary plant secondary metabolites occurring in the order Brassicales with potential health effects, in particular as anti-carcinogenic compounds. GLSs are converted into a variety of breakdown products (BPs) upon plant tissue damage and by the gut microbiota. GLS biological activity is related to BPs rather than to GLSs themselves. Methods: we have reviewed the most recent scientific literature on the metabolic fate and the biological effect of GLSs with particular emphasis on the epidemiological evidence for health effect and evidence from clinical trials. An overview of potential molecular mechanisms underlying GLS biological effect is provided. The potential toxic or anti-nutritional effect has also been discussed. Results: Epidemiological and human in vivo evidence point towards a potential anti-cancer effect for sulforaphane, indole-3-carbinol and 3,3-diindolylmethane. A number of new human clinical trials are on-going and will likely shed further light on GLS protective effect towards cancer as well as other diseases. BPs biological effect is the results of a plurality of molecular mechanisms acting simultaneously which include modulation of xenobiotic metabolism, modulation of inflammation, regulation of apoptosis, cell cycle arrest, angiogenesis and metastasis and regulation of epigenetic events. BPs have been extensively investigated for their protective effect towards cancer but in recent years the interest also includes other diseases. Conclusion: It appears that certain BPs may protect against and may even represent a therapeutic strategy against several forms of cancer. Whether this latter effect can be achieved through diet or supplements should be investigated more thoroughly.

Fermentation can reduce the concentration of health-promoting glucosinolates in Brassica vegetables. The endogenous enzyme myrosinase is hypothesised to mainly responsible for the degradation of glucosinolates during fermentation. In order to retain glucosinolates in the final fermented product, the role of myrosinase activity during the production of sayur asin was investigated. Sayur asin is a traditionally fermented product of Indian mustard (Brassica juncea) commonly consumed in Indonesia. It is prepared by a spontaneous fermentation of withered (sun-dried) B. juncea leaves. The leaves of B. juncea contain a substantial amount of the aliphatic glucosinolate sinigrin. Three withering methods were investigated to obtain B. juncea leaves with different myrosinase activities prior to fermentation. Results show that withering by oven at 35 °C for 2.5 h and by microwave at 180 W for 4.5 min reduced myrosinase activity by 84 and 74 %, respectively. Subsequently, sinigrin was not detectable in the leaves after 24 h of incubation in the fermentation medium. However, withering by microwave for 2 min at 900 W inactivated myrosinase completely and produced sayur asin with a sinigrin concentration of 11.4 µmol/10 g dry matter after 7 days of fermentation. This high power-short time pretreatment of B. juncea leaves contributes to the production of sayur asin containing significant levels of health-promoting glucosinolate. In this study, the effect of myrosinase activity during Brassica fermentation was quantified, and optimised production methods were investigated to retain glucosinolate in the final product.

Thermal processing of Brassica vegetables can lead to substantial loss of potential health-promoting glucosinolates (GLs). The extent of thermal degradation of a specific GL varies in different vegetables, possibly due to differences in the composition of other metabolites within the plant matrices. An untargeted metabolomics approach followed by random forest regression was applied to identify metabolites associated to thermal GL degradation in a segregating Brassica oleracea population. Out of 413 metabolites, 15 were associated with the degradation of glucobrassicin, six with that of glucoraphanin and two with both GLs. Among these 23 metabolites three were identified as flavonols (one kaempferol- and two quercetin-derivatives) and two as other GLs (4-methoxyglucobrassicin, gluconasturtiin). Twenty quantitative trait loci (QTLs) for these metabolites, which were associated with glucoraphanin and glucobrassicin degradation, were identified on linkage groups C01, C07 and C09. Two flavonols mapped on linkage groups C07 and C09 and co-localise with the QTL for GL degradation determined previously.