Although the Japanese became more deeply familiar with the Dutch language (Western knowledge was called 蘭学 rangaku or "Dutch studies"), the Portuguese language also had a significant impact as it was the first European tongue to be heard in Japan. Here's a list of common words still in use today that tries to exclude the many terms specifically related to Christianity, which was introduced by the Portuguese:
バッテラ battera: a type of pressed mackerel sushi that looks like a boat, from the old Portuguese bateira (barco in modern Portuguese)
びろうど birōdo: velvet, from veludo
ボタン botan: button, from botão
チョッキ chokki: waistcoat, from jaque
フラスコ furasuko: laboratory flask, from frasco
飛竜頭 hiryūzu: deep-fried tofu mixed with thinly sliced vegetables, name used in western Japan's Kansai dialect, from filhos meaning sons
イギリス igirisu: the United Kingdom, from inglês
インフェルノ inferuno: inferno, hell, from inferno
じょうろ jouro: watering can, from either jorro (jet, spurt) or jarro (jug)
じゅばん juban: undershirt worn under a kimono, singlet, from gibão meaning short jacket, doublet
かぼちゃ (南瓜) kabocha: pumpkin, from Camboja meaning Cambodia, where the Portuguese sourced the vegetable to import into Japan
カッパ kappa: raincoat, from capa
カステラ kasutera: popular type of sponge cake, from (pão de) Castela
コエンドロ koendoro: coriander, cilantro, from coentro
コップ koppu: glass, tumbler, from copo
マルメロ marumero: quince, from marmelo
ミイラ (木乃伊) mīra: (embalmed) mummy, from mirra meaning myrrh, used in embalming
オランダ (阿蘭陀) oranda: The Netherlands, Holland, from Holanda
オルガン orugan: organ (musical instrument), from órgão
パン pan: bread, from pão
サボテン (仙人掌) saboten: cactus, from sabão meaning soap – I'm sure there's a good story here
サラサ (更紗) sarasa: calico, chintz, from saraça
シャボン shabon: soap, from sabão
たばこ tabako: tobacco, from tabaco
てんぷら (天麩羅) tenpura: tempura, from tempero meaning seasoning, condiment
ザボン zabon: pomelo, shaddock, from zamboa
Note the fact that an inordinate number of these loanwords have to do with food!