Functional foods are of great significance since our society is accelerating into aging. An aging society has many physiological metabolic diseases such as hypertension, diabetes, heart disease, cancer, dementia and geriatric diseases. Fundamental treatments for the elderly are almost impossible and the social burden is heavy. If these diseases can be prevented or alleviated by improving dietary habits using functional foods, the significance would be very large. Pomegranate has been found to have 124 different kinds of phytochemicals. Polyphenols have a wide range of protective effects including various physiological metabolic diseases and cancers. It is necessary to develop functional foods such as preservatives and food extenders which can contribute to food safety, required in the food industry, by using such bioactive substances. Pomegranates have been reported to decrease the impact of many serious illnesses. There is a considerable amount of bioactive substances in the peel of a pomegranate, which has potent anticancer, antioxidant, antimicrobial and anti-apoptotic properties. Unfortunately, the peel is typically discarded after processing. Despite knowledge regarding the bioactive substances in the pomegranate peel and peel extracts, including their functionality and diversity, the knowledge is not well known by consumers in general. The aim of this study was to review up to date research trends for processing and developing new functional foods by utilizing nutritional functional substances, favourite food materials, and materials for processing food contained in pomegranate peels and pomegranate peel extracts. This study will summarize the data found in pomegranate peel and pomegranate peel extract literature mainly recently published in Science Direct. There are polyphenolic compounds (ellagitannins, punicalagin, proanthocyanidin, flavonoids, polysaccharides, etc.) in the fruit peel, making up about 50% of the pomegranate’s weight. The polyphenol content of a pomegranate fruit peel is 149.91 mg/g, which is about 100 times higher than the juice. Paying attention to the fact that the ellagitannin content (14.22 mg/g) in the fruit peel is also twice as high as that of the fruit juice and seeds, that confirms the possibility of utilizing the peel as a food ingredient capable of developing new, functional bioactive foods.

In this study, an environment-friendly synthetic strategy to process zinc oxide nanocrystals is reported. The biosynthesis method used in this study is simple and cost-effective, with reduced solvent waste via the use of fruit peel extract as a natural ligation agent. The formation of ZnO nanocrystals using a rambutan peel extract was observed in this study. Rambutan peels has the ability to ligate zinc ions as a natural ligation agent, resulting in ZnO nanochain formation due to the presence of an extended polyphenolic system over the whole incubation period. Via transmission electron microscopy, successful formation of zinc oxide nanochains was confirmed. TEM observation revealed that the bioinspired ZnO nanocrystals were spherical and/or hexagonal particles with sizes between 50 and 100 nm.

감귤류의 껍질은 플라보노이드의 중요한 소스 중의 하나로서 동아시아에서 내장 및 염증성 질환을 치료하는 민간 의약품으로서 사용되어 왔다. 본 연구에서는 하귤 (C. natsudaidai) 껍질에 포함되어 있는 플라보노이드 성분을 고성능액체크로마토그래피-이중질량분석법 (HPLC-MS/MS)으로 10 개성분을 동정하였다. 플라바논, 플라본 및 쿠마린 유도체는 각각 hesperetin, noviletin 및 coumarin을 사용하여 유효화 하였으며 유효화된 방법으로 정량하였다. 상관계수 (r2)는 > 0.9970으로서 높은 값을 보여주었다. LOD는 >0.01 mg/L이었으며 LOQ는 >0.05 mg/L이었다. 플라보노이드의 총량은 9229.7 ± 0.5 mg/kg 이었다. Naringin의 량이 5010.0 ± 4.5 mg/kg으로 가장 많았으며 sinensetin의 량이 0.6 ± 0.1 mg/kg으로 가장 적었다. 항산화력을 25 μg/mL 에서 500 μg/mL의 농도범위에서 DPPH·, ABTS·+, NO· 소거능 및 FRAP의 항으로 분석하였다. 감귤 플라보노이드의 항산화 능력은 시료의 량이 증가하면 증가함을 알 수 있다.

Tomato fruit color, which is the most visible characteristic among the other fruit traits, is considered to have a substantial influence on consumers. The pink-colored tomatoes with high soluble solids content are considerably preferred especially in Asia compared to the other colors. Generally the pink fruit trait of tomatoes is easily determined by visual examination of intact fruit, however, it is technically determined by the characteristic of the fruit peel. The pink trait is regulated by variations of the SlMYB12(y) gene located on chromosome 1, which controls the accumulation of the naringenin chalcone, which comprises a large proportion of flavonoids. In this study, we developed a derived Cleaved Amplified Polymorphic Sequences (dCAPS) marker and a sequence characterized amplified regions (SCAR) marker in order to discriminate of pink/non-pinktomatoes in the domestic breeding lines. Quantitative RT-PCR analysis indicated that the SlMYB gene is highly expressed in non-pink fruit peel, whereas the expression is significantly lowered in the pink fruit peel. These gene based markers are expected to enhance the efficiency and accuracy of selection pink-tomatoes in tomato breeding programs.

Fresh market tomato cultivars are divided largely based on fruit color appearance (red or pink), which is attributed by the trait of peel. It had been reported that mutation of the Slmyb12 gene suppresses synthesis of yellow-colored flavonoid (naringenin chalcone) in peel and causes pinkish tomato fruit. Whereas wild-type tomato plants synthesizing naringenin chalcone produce yellow-colored peel, which resulting in the fruit appearance to be red. The present study was performed to investigate the association between the Slmyb12 and fruit color of domestic tomato inbreed lines. A SCAR marker was developed from an Indel mutation site (72bp insertion in exon3) of the Slmyb12, and tested on 22 and 18 red and pink-fruited inbred lines, respectively. Unexpectedly, the results showed that all inbred lines tested had wild-type Slmyb12. The full length sequences of the Slmyb12 were cloned from two inbred lines (FCR1 and FCP1), but the sequence alignment did not identify any nucleotide variations within this gene. Furthermore, scanning of SNPs between FCR1 and FCP1 using SolCAP Tomato SNP array) found no SNPs for Slmyb12. To delimit the genomic region of the gene conferring fruit color of domestic tomato lines, we are analyzing SNPs in the genes adjacent to the Slmyb12 using an F2 population derived from FCR1 x FCP1. So far, one SNP located at 1,750kbp downstream from the stop codon of Slmyb12 was mapped using 54 F2 plants and 83% of phenotype-marker association was revealed, demonstrating that the fruit color is controlled bySlmyb12 indeed, or other neighboring gene(s) involved in the pathway of naringenin chalcone synthesis. Further study with more SNPs will clear up this question.